He'll die. The preview for next week's episode shows Jaime on the front lines of battle alongside Brienne of Tarth. Is that worrisome? Hell yeah. He only has one hand, you guys! Jaime is a better fighter one-handed than most men are with two working limbs, but he's going to need every advantage to win against the Night King, so we don't have a lot of faith in his survival right now. This is how we think it'll happen: Jaime will die in battle in Brienne's arms (rounding out his redemptive arc), and later on in the season Arya will take his face and kill Cersei while posing as Jaime, therefore technically still fulfilling that dark prophecy.