After giving it some thought, I imagine that I can get a good mental image of the different hotspots on the map, quite detailed, then during the game, I can sort of Zork style describe the area they see while they travel the overworld, using clues and rumours to get an idea of where they are and where they need to go. Then, once they enter an actual "encounter" area, I can use a battlemap to draw out the area as they see and explore it.
i.e. "After heading southwest out of town, you travel for a couple of hours before you see a divide in the road. The split goes off west into what appears to be the swamp you've come to find, but it also continues on a ways. What do you do?"
"Crossing the bridge leads through a thick grove, but after a few minutes you've come to a clearing. You see a small cottage in front of you, the door is left open, and there's a storage shed to the east. *I draw a representation of these buildings* What do you do?"
Thoughts?