I have two generic hunches.
1) Zelda won't be playable, and might not even feature heavily in the game. The cut scene seems to show them get separated, so I wouldn't be surprised if the end goal of the game is to rescue Zelda again from Withered Ganondorf. I hope I'm wrong, as I'd love to see their dynamic develop all game.
2) I'm still inclined to think that this won't take place in Hyrule, and it'll either take place below or elsewhere. The exploration of open world games is critical, so I just don't buy that they'd rehash the same map with tweaks or additions to it. My money would be on Hyrule Catle being the finale location, but for it to be it's own sealed location either floating high above after being carried elsewhere or capable of being teleported to with it being sealed off or, more likely, only accessible by a long tunnel going way out in any direction from Hyrule. I could easily imagine them separated, Link being swept by the underground river way out from there and connected to a location outside Hyrule, like to the far west or north beyond the canyons, for instance.