Thanks for your idea, Millwright! The only problem with using anything electrical is the fact that we would have to run an electrical line to 3 different places to heat all of them. We don't have anything solar at this point.

CaryC has decided to use these wool blankets to wrap them in with insulation wrapped around the spigots. If this doesn't work out, we will have to go a different route in the future, but we think it will be enough for our winter climate.