Games of thrones

With everyone anticipation the next season of GOT, let's clarify somethings.
Even more troubling along the way have been the actions, or lack thereof, of characters who
do believe in the White Walkers. Stannis took almost a full season to actually head to the Wall after learning about them, and then he marched on Winterfell. When Jon came back from the dead, he first planned on fleeing south before Ramsay’s letter kept him in the North, even though he had been at Hardhome and knew what was coming.

Towards the end of the previous season, the wall destroyed,
With the white walkers matching towards the North, and a dragon to support, it is surely going to be catastrophic, rumors of Nerd Stark son being their leader...

#how possible is that