I agree w/Ringo's response, mostly. I personally have flown the DJI Phantom in nearly 0 degree Fahrenheit weather. Keep the drone battery warm somehow before using....like in your pocket. Realize also the controller has a battery & temp needs to be considered. As Ringo said, sitting a warm running vehicle is a great way to keep the operator & controller itself warm. It's also nice when it's 100F outside to sit in an a/c vehicle.

Realize a couple things....plastic gets brittle at sub-sub feezing temps. Also, I think the rules state something about the drone remaining within the pilot's line-of-sight, but otherwise it would seem the drone would be good for scouting livestock, assuming the sound would not spook them. The newest Phantom 4 does have a new prop design which is supposed to reduce the prop noise.

Re. "prop icing", that may be a problem if there is visible moisture, be it rain, fog, or water droplets of some type. But when it gets close to zero F, it's not as big an issue. That is learned from hundreds of hours of flying in icing in full-size people aircraft. Gotta' be careful of snow showers however, you could conceivably "lose" the drone. Though most of the newer ones have a "return home" feature if you get lost.....and you didn't fly your drone too far away vs battery life remaining.