The big issue you'll have to address is humidity. Zero degrees is okay -- ice crystals are not. Make sure it's either quite dry when you box these items -- or buy some of those dessicant packets to absorb moisture. When you bring the items back into the house, if it isn't warm yet, treat them gently and let them sit in their boxes a couple of days to come up to room temperature gradually. Do not handle them too much and don't plug in anything when it's ice-cold.

Great idea about the dessicants...I never though of that but I have never seen them for sale anywhere...do you know where to buy? Perhaps at a U-haul store?

No idea. Maybe U-Haul; maybe a place that sells storage items? Maybe even a hardware store. Worth a couple of phone calls.

Okay, I guess I have some idea ... :-p