Do you guys think the bottom map will be all the open world of XV?
Maybe the other areas you only get to visit them as hubs accessed via a 'cutscene' driven travel sequence (Altissia will probably fit this description).
I don't think the world is as big as the map, but I don't think it's as small as the minimap either. This presentation demonstrates that there is a lot to this game that they simply haven't shown us yet. I fully expect a few "surprise" areas.