I think all 3 Lannister actors are renewing their contracts for both season 7 and 8. This means that they all survive, at least until season 8... Or their bodies do, like Jon.
Still, I think there will be some animosity between Jaime and Cersei, so he will get over his love for her and either abandon her or straight up betray her in a non-murdering way.
Yeah, Dany needs to get some big L, but I don't think she herself is going down. I say she attacks Tommen's Landing, loses the Unsullied, and one of her dragons shoots a fireball that ignites more wildfire and destroys at least the Red Keep. The Iron Throne is no more.
Up in the Riverlands Arya meets with the Brotherhood, which tries to recruit her for the greater war. She finally accepts that she has a big soft spot for Sandor and he does the same. They all go to the North, Arya only really going to say hi to her siblings and finally sleep in a familiar and comfy bed for a while. They meet Melisandre in the way. Flip a coin, Arya killing her has a 50% chance of happening.
Up in the North, Jon has no idea how to rule and Sansa becomes increasingly frustrated with him because he doesn't catch her hints that LF wants him dead. Eventually, Petyr moves and just as he is about to kill Jon he bursts into flames. The Lord of Light really doesn't want Jon to die. He goes to the Wall to visit and maybe he brings some resources with him. They tell him they've seen Bran and he hasn't left the Weirwood tree.
Jon goes beyond the Wall and Bran tells him everything. Jon doesn't believe half of it (me, son of Lyanna and Rhaegar? Pfff) and Bran tells him to go to Reed for confirmation. Bran says he is staying beyond the Wall unless he gets his marked arm severed, and Jon starts to doubt. Bran tells him about the magic of the Wall and how if he crosses it will come down.
Jon goes to Reed, he gets confirmation about his parents, and goes back to the Wall. He goes and cuts Bran's arm, his sword catches aflame and they go back. Little do they know, Jon cut too low and the Wall comes down anyway.