I believe they should just go all out and make it a giant open world. Close to the size of botw. Doesn't even have to be that big, buy just think of how epic that would be compared to what we usually get from A. C.
Yeah a bigger map would be great, especially if they had multiple landmasses/continents too, and you if could buy a boat and explore the sea :o
Either way I just want a new Animal Crossing game which is bigger and better, but still retains the same feel of the other games.