What would increase or decrease the amount covered is changes in the overall noble-per-region density of the island. So if you can get 50 more people to join the Far East—people who will actually stick around—then we might well stop the glacier early.
If, on the other hand, we get large numbers of people just leaving the continent or leaving the game, we may have to keep them moving farther.
So long as the Dev team is patient with it (I'm assuming so, since it is a moving glacier). I've already emigrated 1 noble, and I'm sure there will others shuffling about until noble density stabilizes after regions freeze. If the western side of Dwilight is cleared, it could take quite some time.
