There is no way I would leave my dog in the car any more then a couple minutes, but some people choose to. For those that choose to, a window cracked open for air would seem sensible. It would also seem sensible that heat would be left on in extreme conditions. Your dog might do well in cold weather, but I'm thinking that is a dog that is moving, running, playing. How long can you sit in the car not moving, no heat, and no window cracked open? On Sunday where I live, someone left their American Bulldog in the car with th heat on while they went to pay for gas. The dog was stolen out of the car and several hours later hit by a car clear across the city. The dog died. Just something to think about, some people aren't right upstairs.
Misty- Samoyed Mix, Tannor- Golden Retriever CGC
Robyn- GSD CGC, TC, Midnite-GSD CGC,TC, Brennan-Golden Retriever CGC, Batman-Husky/Greyhound , Apollo-GSD