Good question. Ideally stay in UK. I love it here as a base. As my kids grow up and parents are elderly i would not leave them. I love Argentina, i love America, like to go to El Salvador.
Once your children are studying, or learning a trade, it gets difficult to leave. If your elderly parents are healthy, they can come with you. Argentina and El Salvador are definitely places that are ascending. If capital gains on bitcoin would get taxed in Switzerland, I would go to El Salvador too. At least for the winters and the tax domicile.