I really don't agree with you about the scale of the world.
The game is real time when it's up to movement whatever the (missing) in game clock is saying.
A usual character run at +-10km/h and our characters are running in real time. Let's say 7 or 8 because they're not running really fast.
You don't need 1 real time hour in game to go from one side of the map to another with real time running characters so no... The map is absolutely not as big as you imagine it is.
And in BG1/2 I could cross an entire "zone" in under 30 seconds - no relevance to scale.
In the Druids Grove, look at the number/size of trees, outcroppings, terrain features, caves, rooms, tents etc....it's a fairly large area - to fit your perception of Act 1 covering just 1 or 2 km, Druids Grove would be the size of a small house and yard - a half acre or so.
