Unfortunately you'll need an address within the surgeries catchment area to register, any gp within the UK will be able to refer you, do you know anyone who lives in the UK who would let you use their address to register?
I'm with the Laurels and they are miles better than CHX so this is a worthwhile endeavor.
After two appointments there they offered to do therapy by phone to cut down on travelling, they said that they'll make sure my endo appointment and my next face to face therapy are booked on the same day back to back to prevent me having two journeys to Exeter.