I was seeing some mold growth in my swamp cooler. It was outside the fermentor, but still not pleasant. I started dumping my old Star San in to top off the water and haven't had a problem since.
Is it detrimental for it to get so cold? Below 50?
I mean, I read that the yeast as a worst case scenario would go to sleep. But when the temp goes up again it would be in your range.
So I guess following that logic you could fill it with ice and by the time you get home you should be in the right range.
I am probably totally wrong though, I'm just guessing.