I think the Hound kills the Mountain, we've been waiting for Clegane bowl all this time, and the showrunners know that. Then, I think Arya kills Cersei using Euron's face, while Jon has to kill Dany because she's losing her mind and wants to kill the populace in dragon fire (betrayed by love). Then Jon ends up on the throne, but doesn't want it, so he dissolves the 7 kingdoms and they fall back to being individual kingdoms, where Jon is still the King in the North.
Jamie is killed by Cersei, Brienne is still with Sansa, who marries Tyrion and rules Casterly Rock, Arya disappears and is the "threat" used to keep the individual kingdoms in line so she starts her own assassin training academy. The Hound dies from his wounds killing the Mountain, Greyworm doesn't survive Dany's insanity, neither does Varys, and Bran stays in the Weirwood to help Arya's group know who to go after.
Probably not much of it is true, but with Missandei's death, Greyworm is absolutely going to follow her and they're setting Dany up to go crazy.