Not me dear boy, I'm a constitutional monarchist, I'm just posing the question.
Charles has a few options.
Maybe not Australia. They'd never put up with it but NZ might just to piss off the Aussies.
Canada's too cold obviously, but look at all those lovely Caribbean gigs.
Jamaica's a bit shooty but the Bahamas or St Lucia would be acceptable.
Just grab as much of his personal wealth as he can, maybe nick a crown and bugger off to reign from a place where he gets to see the Sun more than a handful of days a year.