Electronics can stand cold weather to a curtain extent as per the manufactures recommendations but prolonged exposure at those temps are bound to have a negative outcome in the unit at some point without running. I've used my units before on the ice with no problem but at those temps I was in a shanty. While hole hopping at a little higher temps no problem with a all day trip. I think the heat from the unit while on helps though even if it's small.

Condensation may be a factor if it was left out all week, I would suggest bringing it in and let it set for a day or two before attempting to turn it on. Greg would know better on that part though.

Hope it was not a factor and runs great. Good luck