How to keep jerry cans from freezing when boondocking?

Back on my topic of keeping the jerry cans from freezing, I just measured the area next to my toilet, and we can indeed keep one can inside. We would take it out for showering (we have a wet bath), but it would not be in the way most of the time. So I think that when camping in really cold weather, we will do this as a backup, in case our water lines freeze.