Large island in the North Atlantic, mixed terrain
Economy
Developed/industrialized
What kind of natural resources do we have? Clausewitz made reference to PoFonMobil, so does that mean we have a lot of oil and gas?
Demography
Population around 50 million (most votes were between 25-75 million IIRC, although some voted for a larger population). Note also that a population of that size would imply that we have pretty good farmland.
Relatively high inequality
Relatively large rural population (a lot of family farms?) for an industrialized country
Ethnic composition: Undecided, but based on the geography I suggest Scandinavian with important influences from the British Isles.
OK, so with a reasonable rural population, let's say the population density of Spain - 231 people/sq. mile, so an area of about 216,000 sq. miles. If roughly circular, a radius of about 260 miles. And in the mid-Atlantic. How about:
That's a medieval map, you understand. Unaccountably, the way there got lost for a few hundred years. And now it's back, minus the monarchy, as PoFoLand.