I got part of the answer from this stream:
https://www.twitch.tv/videos/763351879 about 14 minutes in. 3 acts like DOS2 but, as you said, how long those maps/acts are is the question. I never completed DOS2 so act 2 in that game being very long is probably good news for BG3. I'm definitely hoping the later maps are expansive.
I don't know if it is really indication of anything, but if you go to the edge of the EA map, you can see a map of the game and there are like four or five places you can potentially go.
Yeah, I saw that map but I didn't pay too much attention to it. I should probably take a closer look at it to see if it offers any clues. That said, I'm *really* excited to actually see the city of Baldur's Gate in this game. I think my biggest complaint with the EA map is that it doesn't have anything that feels like civilization. I know that's intentional but I live for big in-game cities.