What I will give your argument of moving is that once you have something to fix it usually already have become a feature for someone else. It is usually not realistic to fix much of anything so much as moving in another direction from a different position. I just don't see any places really doing that. Not that it would necessarily be visible, but people are looking. While certainly having slightly different criteria Nomad List for example doesn't feature much in the UK. https://nomadlist.com/

If we had a PR voting system and the PM resigned. What would happen?

Would a general election be called?

It's a bit farcical that the country will have a PM that was not the leader of the governing party at the last election.

Granted with the Brexit mess they could arguably have some legitimate reasons for not calling it straight away but it seems that they've all ruled out calling it at all, AFAIK.

That or turn London into a city state :)