[jasonwatkinspdx]

Discharge rate of batteries falls with temperature. 10C is a very common lower limit for high performance lion cells. There's a complex set of tradeoffs vs fundamental physical limits here. It's not at all a case of "aw shucks we forgot places other than CA exist" which is something you're just projecting onto the situation.

[hinkley]

I had to buy a new battery for my car because despite a battery shop and the dealer saying there was nothing wrong with the battery, short trips in the car below 10C would kill it in a week.

As someone else pointed out, the dew point is not something you want to explore with personal electronics.