I’ve said elsewhere, and I’ll say it again here: the show really makes it obvious why GRRM hasn’t been able to finish the books. 

Let’s not forget that GRRM left them with a mess. Instead of the short, compact stories he had in the first three books, the last two were sprawling, meandering messes. Benioff and Weiss not only had to get to the end of the story, but clean up what GRRM had done with the story. Before they even could get to the end…

I saw it the other way- Sansa made it sound like Cersei might actually win this thing and Jamie realized that he can’t let that happen. Of course, I mainly believe this because I completely and totally believe he’s going to be the one who kills her

yes, but I believe it’s a red herring and Dany will not complete the heel turn.