I try not to be in the Northeast in winter, having paid my dues years ago and then some. However, last I was in British Columbia, I found a garage-doored car wash with *hot* water for USD$0.82.
It. Was. Glorious.
I travel with a 2-gallon manual pump foamer, a couple gallons of distilled water (for car foaming and windshield wiper reservoir), and the usual lotions and potions for paint, glass, plastic/rubber/wood trim, and leather. Washing and drying the exterior is done in just under an hour. Quite the zenlike 2 hours/month.