Exactly, any mid-large breed can handle near arctic conditions-- breeds with a double coat can survive true arctic conditions. My Chow wanted to sleep outside last night and it was eight degrees; I let her stay out a few hours, sound asleep right on the frozen ground-- not even curled up but spread out with her belly on the ground to stay cool... but eventually I let her in, not because she wanted to come in to be warm, because I wanted her to be on the bed to keep ME warm, lol. She hates staying inside when the wood stove is going.
These American Bullies are not “small” dogs by weight, though they do have a short coat.
There could have been contributing factors - the owner did say the dog was sick, though I believe little from this guy (story doesn’t really add up.)
OTOH, we had (one at a time) collies (not “border collies”) when I was a kid, and in cold weather at night, they wanted to be in the doghouse or come in with us. This lead to a hilarious vid which I still hope to find someday, of us kids in the house — I was maybe 6? — sharing chunks of Purina Dog Chow with our collie — my recollection was that it really wasn’t too bad...