The HBO series already diverged from the book's version of events to be a different story. This story tells how I believe the ending should have gone. It borrows/influenced by the amazing work "Ser Davos Saves the Day" however it is an entirely different story. Everything that happened through S7 and before in the HBO series is canon.
College student rent-boy hooks up with a hillbilly rock star driving an old Lincoln Continental convertible, who takes him on a wild, drug-induced all-night, both guys and gals, sexual romp.
Alison Cotton, with considerable help from her parents and two older sisters and an older brother, enjoyed a liberal and varied sex life. When she married Kenneth Jones she promised to love, honour and obey. Kenneth kept his fingers crossed that she would. The trouble is, so did Alison!