There's a lot of time though. It's more a matter of the kids or grandkids moving somewhere colder rather than anything sudden. And the biggest problem with building a new house up north is getting planning permission. The actual construction can be relatively trivial.
It's somewhat ironic all the billionaires are about space and mars and shit - like, ok, super in-hospitable, go for it. While we should be building our space fortresses and geo domes on earth to keep the elements out, and survive on some kind of lab food.
