@PotomacBobFirst, this is event in progress, quite fluid still, and not to be decided or fixed in any form till late autumn at the earliest (my first guess, in case of fast and early decisive Ukrainian victory).
Sure, we can make our best guess about possibilities and build from there. There may be, almost certainly is, value in such discussions, including in fiction. Fictional future conceived at a point of active change may seem short lived, or be perceived as little more than political statement about future to fight for or against, but could also be interesting "archeology" of mind later on.
There's a debate to be had what constitutes victory to whom in this war.
Russia.
Interestingly, Russia have no victory condition, after the first week or so. At all. Therefore it can't possibly win this war, and they know it. They can capture territory, kill, rape and torture, deal tremendous amounts of matererial and emotional damage, but cannot win, because no more a condition for such victory exist in this reality. Losing is existential threat however, as their very reality may case to exist, so they fight on, as senseless as it is, in hopes the holy sacrifice of war will cleanse their world of the incomprehensible.
Closet to a victory condition that is left to them would be, to kill, wipe out Ukrainians as nation and nationality, including any memories of such, or at least pervert, belie it as part of current ruscism, and enforce that understanding on anyone, anywhere. That's a goal that's exceptionally hard to achieve, to not say definitely impossible. But that's why they burn books in occupied towns, deliberately target schools and houses of culture and museums, and torture civilians forcing to publicly denounce their national identity.
NATO, it was just red herring, just airing grievances producing excuses. The goal was to rebuild the Russian empire at its widest possible extent. It was impossible to do so without Ukraine, seen as integral part in many aspects, including practical but also many irrational and very complex to explain. But swift, victorious capture of Ukraine, its infrastructure and production capacity, from food, to weapons, to shipyards, to computer chip precursor materials, to talented programmers and highly intelligent, hard working population in general (very different in construction from Russian own in many ways) had to be just the first step on the grand war of re-conquest of the lost lands.
Putin went for a war that literally make no sense on an array of gravely flawed assumptions, from a position in wholesale alternative reality he had believed. Since Ukrainians didn't give up welcoming Russian troops as liberators from perverted imported regime forced on them by Americans (or maybe British agents, but that's basically the same) that reality ceased to exist, but war... war between those realities continues. Can a war force a wholly invented reality into existence? To an extent, in areas under absolute control it's almost possible, taking Orvel's "1984" for a manual.
World where Russia achieves any degree of victory in this war is a bleak place, where democracy and rule of law fails worldwide giving rise to neo-feudal order fueled by fascism, evangelical belief and rampant anti-intellectualism letting small minority usurp rights on diminishing knowledge. It was so close, still may be, all it may take is Republican victories in the next two -- and last ever! --, elections in the U.S.
Ukraine.
Ukraine fight for survival, once again, as they have had to do almost once a generation for almost a thousand years by now.
There's lot of confusion about the "brotherly nations" painting the war as almost a civil war inside something bigger.
Yes, history of Russia indeed started in Kyiv (aka Kiev), when Oleg, the regent of the underage son of the swedish guy (possibly Estonia born drunk) the Novgorod nobility invited for a king after their democracy failed took the city from... probably Hungarians, in today's terms.
To not digress in any further in abyss of extremely tangled history I myself don't know as properly as I might want, let's take this for a quick simplification: the cultural divide between those two Russias currently at war (there's many more, both physical and mental, including Serbia) may probably be best defined as between those who get enslaved by Golden Horde (an illegitimate daughter of with Muscovy still is) and those that remain independent forming a broad coalition that stopped it from entering Europe further, also known as Great Lithuania.
So the war in Ukraine today, it's still war between Lithuania and the Horde.
In defensive war between civilizations there's many possible graduations of what victory may mean. Retreat is hard but legitimate option. At worst, whole nations may move from burned out lands in name of survival, possibly in hopes future generations in better times may be able to return.
Ukrainians are no strangers to loss and changing borders, theirs been all over the place through times, some even still insist they hold claims on Belgorod and Krasnodar as ethnic lands lost just in previous genocide. As it often happens in Borderlands (what the name Ukraine literally means) the actual borders may be seen as somewhat arbitrary. However, borders hold symbolic value, and this is a war of symbols.
The symbolic war Ukraine is currently winning exceptionally well. Not only they didn't gave up to be colonized again, the way they managed the nation to be redefined, recognized and even celebrated as never before is truly a historic moment for them. As any gains in a war, those aren't still final, there's still many battles to defend what's born in this pain. The continuous suffering, the future victories or defeats in the physical plane, as well as the rebuilding phase after the war (however it may end) may well redefine things anew again, holding risks and unknown unknowns.
The physical borders matter too a lot of course. From landmarks and options of force projection to trade routes, to minerals and hydrocarbons, even totally devastated lands hold tangible value, probably even worth waging war for.
Ukraine in 1991-2014 borders (or even, in the borders as ambitiously envisioned back in 1919, locking Russia out of Black Sea access completely) could have potential to become regional power and power center in European Union in par with Germany and France, even without the broader east-central-northern belt sub-coalition (from Moldova to Finland) they could easily find themself as a leader of, just by mass, but also mentality.
While much reduced, perhaps even landlocked (although that may seem all but ruled out at the moment) Ukraine, with many refugees that never return after long years of war and total destruction
Crimea.
I often say, the whole war is still first and foremost about Crimea. Defined in this very narrow frame, the Russian victory would be forcing international recognition of its annexation, and Ukrainian victory would be getting it back.
Historically, Crimea isn't quite Ukraine, nor it is Russia either, just as well it's Turkey, if not Greece, even if those times seem so long gone. Perhaps it could be an independent republic, although that window seems lost, it's much too damaged by Russia now, but who knows.
Crimea lived under its own rules even in Soviet Union (as did Caucasus more broadly, so making Crimea Georgia, perhaps) despite the total deportations of Crimean Tatars. Eventually, some of them returned home.
Under independent Ukraine, Crimea was poor (along with enduring hardships of the host nation), but very much free. Including, the nudist beaches were blooming, finally official, freed from the slippery unrecognized status back in Soviet Union.
It surrendered to Russia easily in 2014 as most didn't see a difference, "could not be worse" they said, and Moscow even was richer than Kyiv, so perhaps they might too. Moscow, however, returned with renewed repressions, redoubled colonization efforts and rampant militarism. Almost a million people moved in during those eight years, mostly retirees lost in sentimental past, but also soldiers and their families. And that's while Ukraine cut off the drinking water. There used to be even rice fields, now laying bare and dried. The new Russian occupation years had been unending crisis for the locals, political, economical, and social, in a regime harsher than Russia proper and poorer than even in Ukraine times.
The War.
(To clarify, I'm not there, on the ground. I have, however, somewhat obsessively, followed it, as it's seen as existentially important for my own country and thus quite literally to personal happiness.)
It's currently impossible to predict when Ukraine will win, and how decisive the victory will be. The war can end in many ways, from ten days to ten years from now. I'm still optimistic, believing we live the darkest days of it right now, soon to be turned around, but I feel forced to reconsider my initial predictions (from still back in February) that Ukrainians will be at Sevastopol by midsummer, by as much of two months if not all four. Then, I said Kharkiv will fall, and it haven't, and likely won't. Entering Crimea may be difficult, and best done in fast, sweeping attack Ukrainians may not be able or willing to mount, but not trying to bring the war to Crimea at all could prove to be strategic mistake, on a symbolic level. Taking Sevastopol by force may be near impossible though, but likely unnecessary either.
Some possible outcomes:
-(1) Russians go home by choice
--(1.1) Putin himself declare the special operation full success and retreat to February 23 borders. Can happen anytime, although seems utterly unlikely right now. Well communicated imminent total collapse of Russian army may trigger this. Preventing such to manifest on battlefield would indeed be colossal and unlikely success.
-(1.2) Putin dies or is ousted; the new administration recognizes failure, blaming crazy Putin and western weapons, and retreat to February 23 borders. May happen anytime, but perhaps need way more damage to Russian army still, and at least some, unquestionable strategic success in larger counterattacks by Ukrainians. Imminent total collapse of Russian army recognized in time may trigger this, but may not be necessary. (The decisive defeat of Russia in Kyiv adventure don't quite count, because Russians managed to -- mostly -- escape; that rescue might well remain the most successful Russian operation of this war.)
-(1.3) dramatic regime change happens, and... nice to fantasise, but unfortunately, impossible.
-(2) Unfair premature peace is forced on Ukraine
--(2.1) by imminent sudden collapse of Ukrainian army, recognized in time. May happen anytime, in theory, even if seems highly unlikely right now. Total loss of long range air defense may trigger this, or extreme loses in series of small encirclements.
--(2.2) by collapse of Ukrainian economy. I think this is what Russians actually aim and hope for. It's easy to say that no amount of hardship would buckle Ukrainian resolve, as a statement made from comfortable distance, it may not be that easy on the ground.
--(2.3) by international partners. May happen almost anytime, perhaps triggered by global economic crisis, but also there's all those talks about "saving Putin's face" or "giving him an off ramp" that are imho outright sabotage on top of plain stupidity.
--(2.4) by unbreakable Russian defensive line, perhaps after Russians already have reached at least Luhansk Oblast border. Could take up to year of positional warfare and drying up western support to recognize the stalemate.
-(3) Ukrainians win on the battlefield
--(3.1) after Russian army collapse. I won't currently bet on this, even though Russians are again out of reserves indeed, but in theory, even relatively limited offensive success may trigger this and rout the rest. Anytime, started from, maybe a month from now. If it happens, Ukrainians go forward until meet renewed resistance or reach border. Supposedly, the chain of events is dramatic enough to force Russia to recognize failure and seek ceasefire. I wouldn't bet on that happening either.
--(3.2) after Russian regime collapse. Even the most dramatic events in Moscow won't end the war immediately. Lack of any, or confusing orders from the metropolis may lead to relatively quick defeat in uncoordinated piecemeal fashion though.
--(3.3) by reaching border of their choice in result of successful, grinding campaign of piecemeal attacks. There's several possibilities where those borders may be. It can be done in stages, testing Russian willingness to agree on negotiated retreat from the rest of the country, then attacking further if there's none. If that goes long and successful enough, Ukrainians may end up in Russia in some places, although I have heard only extreme dislike of even such an idea by Ukrainians themselves. There may be protracted artillery duels lasting years at those borders, those may serve as yet another reason to take buffer outside the country.
As I said I don't expect any resolution before October, maybe September at the earliest, and that may require a collapse of one or both armies. Some say, the war will last in total a decade with new flare up every other year. That's certainly possible, as long as Russia remains more or less intact, and even more so if it devolves in gang warfare and internal civil wars. In such, some factions will prioritize killing Ukrainians over anything.