Thanks for that Martin.
We managed ok to fill up 19.5 litres at 59.7p/litre at Morrisons Catcliffe yesterday.
We had almost used one Gaslow bottle full over 3 chilly nights at the THS at Harrogate! At that usage the option of £4 a day for electric hookup doesn't work out much dearer.
I think the BP in Darnall Sheffield still has it.