This will be a most interesting and demanding test of the equipment for sure. Keeping the batteries warm will be critical, but the retractable lens/cover system will also require warmth. We have had film become so brittle that it would snap or the socket holes would rip out.
For a system this small, one would probably have good luck using chemical handwarmers.
It will also be important to keep the rig in a waterproof container, like a heavy plastic bag when it is brought "In From The Cold" to prevent condensation buildup until reaching room temperature.