AJ has his bed set up at the foot of mine. When it gets really cold outside, the bulkhead of the truck gets cold too. It's the only time he's allowed to sleep under my blanket.
I would like to try boots on him this winter. Since we are all over the country all the time, he never has a chance to acclimate to any specific area. He's most comfortable between 50 and 80 F(10-27C), but he can handle being outside for brief periods when it's really cold.
My concern, however, is for his feet when it's sub-zero F. (He only goes out on a leash) He goes to do his business, but on his way back to the truck, he starts picking his feet up like they hurt. (And gives me a pathetic "help me" look) I carry him back to the truck on those occasions.
I have a safety vest that doubles as a rain jacket, but he won't wear a coat that covers his legs or chest. He just hurries up when it's cold.