There's definitely something magical going on with The Wall
Even though Benioff and Weiss don't consider the Night King to be the show's primary villain, the plot's momentum suggests he'll eventually have to get past that damn Wall and unleash icy hell. After all, winter is coming, as the saying goes. Fans have long speculated that an object mentioned in the books, the Horn of Joramun, will ultimately be used to bring down The Wall, but by now show-watchers know that Benioff and Weiss have been known to zig when George R.R. Martin zags.
"We don't want to give away too much," the pair writes. "There are the books, and the show, and it would be a disservice to both if we went into too much detail of, we're going to use this or that. We're not using that. What's laid out in this season is, very clearly, The Wall isn't just a physical structure that is keeping the army of the dead out. If it were, and if the wildlings managed to make it over, at least in theory someone like the Night King has so much more in the way of both power and troops who'll do literally anything he says."