Sadly, I can't - but thought I'd cheekily piggy-back your post as I'm looking for a good, qualified equine physio too - but in Shropshire. Maybe by keeping this UP, we might both get what we want!
OP your vet should hopefully be able to recommend a good one? Mine did for me - there is just 1 they recommend and she came to my boy on Monday and frankly she is brilliant.
So if your vet cannot recommend could you ask a local event or dressage yard for a recommendation?
JG - not sure if she travels as far as you but we had Joanne Andrews to our boy & she was brilliant. She's from the Southport area but I know she travels north at least as far as Lancaster so it might be worth asking if she does long trips south too.