Well, with a new Squire you are probably looking at a polyester or UV cured polyurethane, which are more "elastic" finishes than nitro, so there is every chance that you would not have a problem in any case. HOWEVER, it is still wise to take some precautions.
Basically, what happens when you get a guitar too cold is that, when it warms up, the wood expands faster than the finish. This causes the fine cracks in the finish which are commonly called weather checking. This is NOT a structural issue, by the way, just a cosmetic one, but if you can avoid it, why not, right?
The way to avoid it is to bring the guitar up to temperature as slowly as possible. The most important precaution is to leave the guitar in the case until it has had a chance to come completely up to room temperature. The longer you can draw that out, the better, so it is advisable to not only leave the guitar in the case, but to also cover it with some kind of insulation (wrap it in a nice thick comforter, or something similar). If a guitar has been shipped to you in cold weather, leave it in the box for a day or so, unless the box shows visible signs of damage (in which case you need to check things out so you can make a claim against the shippers insurance). In most cases, we like to let guitars sit in their cases for a day or so to come up to temperature.
By the by, when cases come into the shop cold, we often keep them closed, and do our normal evaluation and estimate the next day over the phone for our customers. If you live in a climate where this is a serious issue, I would expect your repair shop to know to do the same if you bring in a cold case.
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M.K. Gandhi