For example, Chaim has said that even though he would rather live in a warmer climate he will not be leaving the place where he is unless it is to Israel. I think this is the spirit that this law is intended toward.
I'm not sure perhaps Chaim can answer why he said this- perhaps a Middat Hassidut on his part, but I would think that if he would move out of NY to let's say Florida especially under the circumstances he is currently in (physically being prevented from fullfilling the Mitzwah) he would be allowed. Perhaps he does not want to move to a place where he will enjoy which might take his mind of yearning to go up to Israel.
Also their are ideas and laws of not majing the Galut a permanent dwelling but something that is temporary (for example not exceeding a certin amount in building fences around one's property, I believe soo not to make extremly permanent dwellings outside the land).