I often read threads with people asking questions about returning to the UK and my immediate thought is "why the UK?" If for some reason I stopped enjoying life here the UK wouldn't be top of my list for countries to live in - in fact I don't think it would even be in the top 10.
In no preference order I'd be looking at southern France, Romania, Morocco, NZ, Argentina or maybe Sweden. Returning to where you've come from sounds as dull an option as going on holiday to the same place twice. So, where would you go?