I finally created the map using the Hexographer. It covers about 400 hex fields. I am not yet sure about the scale of the hexes. But I think I am going with 6 miles per hex. That's still a fairly large area. Considering that there are no roads and the terrain is either swamp, hills, forest or all of the above, an average adventuring party will cross a two swamp hexes in 3 days or three forest/hill hexes in two days.
