What freezing water butt

Over my birthday - end of January to first week of February - my wife and I went to Broadway Caravan Club Site for 10 days in our Lunar Caravan.   First I should say that the site was great, but the temperature minus 5 degrees over night and we had forgotten the home made thermal protection I had made for the water butt.   The waste water container froze solid, the water butt and pump froze, I managed to get the pump clear and the ice out of the water butt, I then found a B and Q and got some silver thermal wrapping for the water butt(cost £12), wrapped it around the butt and pump connection.   Problem solved.   The waste water butt I managed to get clear of ice and from then on didn't use is, putting all the waste water into the washing up bowl and taking that over to the waste water point for disposal.   I would say that having solved the problem we then had a great time visiting Broadway and the surrounding area.   Even the snow inch of snow that fell didn't cause us any problems.