Two of mine are blanketed and two are just wooly beasts. The appendix mare has a very fine, thin winter coat, so she gets a blanket all winter. We changed it up for an even warmer version today as temps dropped down to -42 with the wind. My pony mare is only blanketed because she has been in training for the last two months, and worked regularly indoors. Now that she is home and temps have plummeted, we have to keep her blanketed for a good while yet.
When it's really I cold, all the horses get extra hay and extra grain. I think the cold is much harder on me than the horses. They seem to pick the coldest day of the year when hubby is out of town to break the fence, so I was out fixing fence after work tonight. My old guy also managed to pull the insulating layer off the water trough today. Thank goodness we have plug in heaters, but I didn't appreciate having to fix the trough in this bitter cold. Lastly, there was a tiny bit of water left in the garden house we use to fill the trough. I was just enough to freeze up and plug solid between the insulated garage and the outside faucet, so now I have to thaw it and then blow it out before going back out in the cold to fill the trough.
Yea, winter in Canada is awesome. Not!