[EVERYTHING] Speculation on events leading up to season 8.

I'm under the impression that if the expedition beyond the wall goes according to plan, Cersei is going to try to lay a trap for Jon and Dany when they bring a wight to King's Landing. And I think the only way for all three leaders to team up, which the show seems to want in order to fight the dead, Cersei will need to be killed/replaced and I think Jaime will understand that. He will see the threat of the dead but Cersei won't. Which will lead to her death by Jaime. I think Jaime will take over the crown somehow (legitimate claim is not there so I'm not sure, but neither was Cersei's), in order to set up the final season. Thoughts?