I looked at the countries which don't have an extradition treaty with the UK, but these are mainly places like Afghanistan, North Korea and Somalia, so I might need to rethink my plan !
It's a pity the UK signed a treaty with Brazil. Ronnie Biggs from the Great Train Robbery in the 1960'swent to Brazil and couldn't be extradited, then made a career out of hosting barbecues at his home in Rio where tourists could meet him. It became a right of passage for British rock stars to go over and have their photo taken with him