Jon kind of has to be alive in some way or another. Without him there are no characters to continue the story in the north. I mean, who would we start to follow in his place to learn about the white walkers' invasion and such? Would Tormund suddenly become a POV character? Thorne? Not even Sam is at the wall anymore, and I'm sure they aren't going to continue Jon's story using a bunch of second-rate characters like Melisandre and a few named brothers of the watch.
