Eiji Aonuma has confirmed that The Legend of Zelda: Breath of the Wild will have no Loading Screens in the Overworld!

[Ljink96]

Hiku said:

Ljink96 said:
So I expect that going into houses won't require loading times either, that's great. I kind of hoped it would be like that after seeing the woodcutter's house in the demo. I know Nintendo's hiding so much from us, can't wait to see what this game has to offer!

You think? I know Skyrim usually has no loading times on the map (except if you fast travel), but entering houses does.
Same thing in Dragon Age 3.

I think it's possible. Especially if Nintendo wants to make it a truly seamless experience. Similar games like Dragon Quest XI have seamless entry into buildings and structures so I think it's possible, then again that game's running on PS4 not Switch/Wii U.