2-Bran will not leave the cave.

I like this one - but only for the following reason:

GRRM has spoken about the ending being bittersweet. We also know that Bran would be very powerful if he takes Bloodraven's place on the Weirwood Throne.

Bran would be able to affect events in Westeros. His impact would be so great but he'd never be able to have a normal human interaction again. He could see those he loves and potentially save theirs (and humanity's) lives but never speak to them or be with them ever again.

Given conditions at the time Bran makes it to BR's cave, it is basically improbable that Meera and Hodor could make it back alive.

As a result, Bran's family would never know what became of him or of the impact he has on their lives. Through the weirnet, Bran would be "so close yet so far" from them.