But it's not just Tormund that you need to be concerned about because another fan favorite is most likely headed that way too. In his fire vision in the first episode of Season 7, the Hound described to Beric Dondarrion seeing a castle located where the Wall meets the sea and the dead marching past a mountain that looks like an arrowhead. Considering the place Tormund is going to is called Eastwatch-by-the-Sea and is described on the Game Of Thrones wikia as a "castle and port located at the far eastern end of the Wall, where the Wall drops into an inlet of the Shivering Sea called the Bay of Seals," that's probably the location the Hound saw. While Huffington Post noted that there are no mountains in that area and that the arrowhead vision could be a reference to the Hound eventually battling with his brother the Mountain, it still seems that the Hound and his new Lord of the Light-following buddies are headed in the direction of Eastwatch.
While that's good that Tormund and his Wildlings could have potential badass backup arriving in the form of the Brotherhood without Banners, would their combined forces be able to stand against the Night King and the White Walkers? The sea could provide a natural barrier for the men and give them an advantage or at least a getaway since Jon Snow escaped from the White Walkers on a boat after the battle against them at Hardhome in Season 5. Yet, as fans noticed, the shot of the Wall during the opening of credits of Game Of Thrones changed for Season 7 and it now shows that the sea on the eastern side of the Wall has been frozen over. That could mean the Night King, the White Walkers, and the wights would easily walk over what used to be water.
Just to really cement that the White Walkers are going to Eastwatch, which will lead to a horrific battle either in the episode of the same name or future episodes is the fact that Jon says to Daenerys in the "Eastwatch" preview, "Bran saw the Night King and his army marching towards Eastwatch." That's accompanied by a shot of the White Walkers, and whether that's just from Bran's vision or from what Tormund and the Hound will face is not clear.
Although the White Walkers weren't prominently featured in the first half of Season 7, "Eastwatch" is a turning point for these cold villains, who will probably be more of a presence for the rest of the season beyond the fifth episode. That's because Jon is shown fighting the White Walkers in the second trailer for Season 7 and I'm not confident he'd be able to travel from Dragonstone to Eastwatch in the span of one episode. (Although, it's possible since the characters have been traveling much quicker nowadays.) Still, with an impending battle at Eastwatch, the White Walkers will be getting closer to the humans and so a large portion of the last three episodes in Season 7 may be dedicated to the men — and women — of the North attempting to fight them off.