Well for me personally I have a heated garage with warm and cold softened water taps.
BUT at -4(-20C) and -13 (-30C), i have a few tactics to keep it warm!
First on ebay for $50 i bought myself an electric patio heater that i turn on roughly 10 mins before I start washing and correcting, i can be comfortable in jeans and a tee for hours on end.
If the paint is still too cold after a hot wash, i point the heater at it for a couple of minutes to bring it up to around 70 (20C).
Having one of these guys is really helpful, especially for certain sealants that require specific temperatures
MicroTemp MT-PRO Digital Infrared Thermometer
Really for your products, as long as it stays above freezing, your soaps, APC, cleansers, and compounds will be fine. Ive always kept them in my garage, never had a problem. Although super cold days id just put a space heater on the shelf and turn it on!
Wax and sealants on the other hand Id recommend keeping them inside, when the wax freezes or gets to near it ruins the "temper" making it a goopy consistency, rendering it useless.
But if you have any questions feel free to ask!
-ps welcome to the forum!