The other poster is correct that film isn't harmed by a brief defrosting as long as you don't get condensation on it (it's packaged in airtight plastic canister

The other poster is correct that film isn't harmed by a brief defrosting as long as you don't get condensation on it (it's packaged in airtight plastic canisters or foil wrappers). As long as you don't let it get hot like sitting in a car or something... But unrelated note, get an upright/freestanding/chest deep freezer. With a normal fridge/freezer, when you open the door all the cold falls out. The upright freezers form a "well" that keeps the cold in much better. They will hold a freeze for at least 24-48 hours if you don't open the lid, although much longer and you would probably want to be looking for a generator.