That foam insulation alone wasn't enough for me. I put some foiled bubble wrap from Screwfix around as well.
Also go a 2kw thermastatically controlled oil filled rad (also from Screwfix) on low power (400w) at night and insulated van walls and roof. Toasty in there now. My static system in garage has two frost watcher heaters and I've insulated everything I could.
I could work if there wassn't so much snow about. I don't think custys will want me splashing water about and I think the hose will freeze in no time on the ground even if my water was heated. And it's so slippy everywhere.
Whilst lagging my pipes I had a cup of tea in the back of the van and it was stone cold in no time at all so I imagine my water would do the same once out working.
I'm just gonna take it on the chin and sit it out. Gonna take me months to recover in terms of money though.
But hey, nobody's died or anything. Could be worse, you could be in Afghanistan or something.