3 or 4 weeks ? Maybe more
as you imply
No cooking
No hot water
No heating
What model fridge do you have. Some of the AES ones can switch to solar power when your batteries are topped up. You would need to do a bit of a Mod but it should not be difficult.
Why not use Local gas...
Leave room on the locker for a spanish portugese bottle.
Yes you need pigtails..
Buy and use a local bottle and swap it out as needed..So your uk bottles are reserves.
I like re-fillable but many on wildcamping have suggested this.
And or use local bottles with bbq..
Certainly use local wine to overcome any probs !