I spent three years in the Air Force near Fairbanks and recall a three week stretch of 48 below at night, warming up to 45 below during the day. Sun barely broke the horizon.
Anyway, not sure I'd bother with cattle considering all the hay you would have to throw at them.
Having said that, we visited Fairbanks a few years ago and I noticed a herd of angus near there. Fortunately cattle are pretty big heat producers - their rumen is like a steaming compost pile. Which is why heat stress is a bigger problem than the cold in most of the country. Especially after we turned most breeds black, which makes them hotter. Though black doesn't help absorb sun rays much in the winter, as it is generally cloudier, and the coldest temps are at night.
Would probably be good to have animal with more body mass, as that would keep them warmer. Which is why angus might do better than Dexters.
Here are photos near Fairbanks:
