Doesn't every new continent now get progressively larger, with more lieutenants? If not, they should.
Great idea this would really make the later continents tougher.
Would it? it would make them take longer, but it wouldn't make it any harder.
and to the general point of large continents, I barely visit 1/3 of the individual regions in a normal continent, making them larger just means there will be more places that I ignore. Rather the extra size won't add anything, except perhaps forcing you to do a couple of extra wind shelter missions.