I’ve been playing with some campaign ideas, and one thing I am considering is making a world setting where complete sub-continents are essentially cut off from each other, in the same way they actually are on Earth. If we presume that for whatever reason very few people travel very far due to technological stagnation (I think there is an argument for magic making globalization come about sooner), then one could have multiple settings near each other, just waiting to spill over into each other.
So how big is an idea region for adventuring? How far have you gotten? I’ve hardly ever played in an area more than a few days walking distance across. Pacing has just played out that way for me, so what is your experience?