I'll be moving to Buffalo, NY from the Faroe Islands. Looong flight. About 15 hours or so(that's including the waiting time between flights of course). Last time I visited I flew from the Faroes to Iceland, then Iceland to Boston and then Boston to Buffalo. And it's not really possible to do it much shorter than that, I think.
The longest actual flight is 6 hours. That's from Iceland to the states. But suppose that doesn't really make much of a difference, since I reckon just being in the crate in unfamiliar surroundings is stressing enough, so being in the air or not doesn't really matter

I read about that temperature thing earlier too. Gotta look closer into that.

Found a great website actually, where they apparently can do all the preparation and so on for you. It's probably a lot more costly but definitely worth a look to make sure everything is in order. I don't wanna risk any paperwork and so on not being in order, that's for sure.

This is permanent of course. Otherwise I would not even consider it.