The art of taxation, @Tummyachey , is the art of plucking the goose to get the most feathers with the least pecking and hissing. Attributed to a c16th French finance minister (Colbert IIRC).
We (DH and I, both edging 70, and verging on retirement) are considering exactly this decision. Financially and tax wise, we would definitely be better off selling everything in the UK and moving to say, Antigua. It's English speaking, and citizenship is available for an investment of $120k. There is no IHT and English common law. Provided we buy decent health insurance for us both, and choose a house with adequate water storage and solar panels/batteries, then there's a lovely sunny life to live while we last.
Or a European country with a retirement visa system: again, I'd be paying medical insurance premiums but in, say, Portugal I'd also only be paying tax on income at 10%. No IHT.
In reality, I don't like the Caribbean (apart from the beaches) and I don't want my DH to have his next health crisis (there will be one) in a country where I am not really fluent enough in the language to speak to the doctor. I can do so in French and in another year, I would hope to be able to do so in Gallego Spanish/Portuguese. In reality, I shall aim to arrange our estate in the best interests of our DC, including PETs for a house, and cross my fingers that nothing goes too badly wrong too soon.