I had my RS-1 in the back of my car where it dropped to 28 or so. This was just overnight, but they were fine. I'd think it would be more important to wrap/box them so no critters can get to them and so they stay dry.
As Uncle Erik mentioned: make sure they stay dry. What would most likely kill them is when you bring them out of storage and water condenses inside them and possibly shorts something out. Wrap them in a blanket and stick them in a nice dry box or air-tight container and you should be just fine.