You're going to struggle getting LPG in and around Wells.I believe Bawdrip fuel station stocks it on the A39 on the way to the M5.
What I recall is it's a small fuel station with a bloody low canopy !!!!.
Personally I'd run home on petrol........certainly not worth damaging the Rv !
I believe a lot of petrol stations are not stocking it anymore and that's going to be a pain in the arse as we all use LPG on board.My nearest one is the Esso station at Podimore on the A303,Fortunatley they still stock it there.
Enjoy Wells and Cheddar.........If your Mrs wants to spend some money then have a day at the Clarks Village in Street
We have down loaded an app on our phone called myLPG.eu which seems to show location and price but not if RV friendly. Thanks all for your help and advice. Look forward to meeting up with you when times are safe.