Been there last year I helped move a friend out in -26ºC and again this fall we helped move a breeder out it wasn't super cold but about 10ºC I think. All in all no RI or any other problems (accept finding enough snake bags for the breeder... 160 snakes is quite a move!) I assume you have a car or something?

What we did is quite simple, We packed all the snakes in snake bags and into a cooler that had been warmed up (over turned over a forced air vent) A warm towel was placed inside on the bottom and then the snakes and finally a towel over the top. We had already made a run or two and the car was warm but had someone in it keeping it running so it was warm inside. Once the rack was loaded and the car ready to go we closed the cooler (actually the towel over the top and then closed the cooler) and walked it outside closed tightly and to the car (about 5 min away was the best we could do) The cooler was placed in the back seat of the warm car and off we went. After about 5 min or so the outside of the cooler was warmer and then we opened the top and pulled off the blanket. The thermometer read 84º and it started at 86º so no problem. The car was about 79º inside but the cooler didn't drop much more than 83º over the 45 min trip before anyone got out we just sealed it up again, and walked it in.

The rack however arrived off the back of the truck fridged and even with the heat turned one and everything plugged in it took hours to warm up fully so the snakes spent the night (well what was left of it anyway) in the cooler and snake bags with the lid opened we just cranked the room temp up to 83º The other move was much the same only we used just a unholed tubs for the transfer.

Hope this helps!