The op suggested they would be stopping in caravan every few days so ok to leave power & heating on. I'm failing to see any insurance implications. When I go off on an extended caravan trip then I do indeed turn of water/gas/electric at home but I wouldn't bother for just a few days.
As well is two words!
How does a sage know everything about everything? or does he? or does he just think he does?
Remember, if you buy something you bought it, not brought it.
Always drain down if away from the van and leave taps open over winter weeks. Otherwise no problem to leave as normal. Heating on low should be Ok...but always watch for condensation issues...