I accidentally left mine out in the garage overnight in that weather last week, -15 here too. My Cell turned all sorts of pretty colors, but no cracks. I regularly leave mine in the car at work on bowling nights, no cracks. My teammate never leaves his in the car, and his Shift cracked all the way around last week. Go figure.
I don't necessarily think it's cold that cracks bowling balls, but rapid change in temperature. I also think that the quality of the original pour of the ball has a lot to do with it too. The one thing I wouldn't do is throw a frozen ball, I always let mine warm up before throwing them.
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-Clint