Well, if the laptop screen is kept off and the laptop is modest (and it can be) the power draw might not be very much for most of the night. Personally I was more dubious about the cooler running "at max power" because there's no reason to cool that chip to less than -10C and that would be a very low power draw on a cold night.
Some good points. My headless mini-pc draws less than 20W compared to 65W for the laptop with the screen own at lowest brightness.
Would like to hear from MTC given these questions