My theory for next episode is that they won't be able to just bring back one white walker.(I mean I don't see that as a possibility personally.)
Theory
After a decent battle they realize it wont be possible and retreat.
Someone is injured by the Night King.. stabbed or w.e(My personal pick is Jorah Mormont)
John having fought with the Wildlings vs White Walkers knows that if he dies he will reanimate and turn into a Wight to fight for the dead.
Jorah finding this out decides to be the sacrifice as it will save everyone else he is with and give proof that Dany needs. In other words everyone would travel back to Dragonstone and Jorah would die/turn into a Wight in front of Dany.
Just my own little theory I came up with although not sure if this is even possible lol
(By travel time it shouldn't be but the teleporters they got in GOT are pretty efficient)
Theory
After a decent battle they realize it wont be possible and retreat.
Someone is injured by the Night King.. stabbed or w.e(My personal pick is Jorah Mormont)
John having fought with the Wildlings vs White Walkers knows that if he dies he will reanimate and turn into a Wight to fight for the dead.
Jorah finding this out decides to be the sacrifice as it will save everyone else he is with and give proof that Dany needs. In other words everyone would travel back to Dragonstone and Jorah would die/turn into a Wight in front of Dany.
Just my own little theory I came up with although not sure if this is even possible lol
(By travel time it shouldn't be but the teleporters they got in GOT are pretty efficient)