Current map is v mountain heavy and its a pain in the ass to get anywhere. You're right in saying that there needs to be ample low land, though.
Personally, I prefer a big map and fast travel to be available. Not only does this give the impression of a vast fantasy world and keeps the sights from going stale quickly, it also allows plenty of space for player groups and allows powerful nations to project that power through size, as is done this map. Dont make it smaller, just make more of it usable and stop claiming large swathes of the map for "map lore and events" only for it to barely be used at all