Pellet feeds?

If it is just to get a supplement into him with a little extra calories I'd go with alfalfa pellets (soaked) or some soaked beet pulp. High fiber to help keep him warmer and good for mixing powders The other pelleted feeds won't hold the powder unless you moisten them and they'll probably provide other things he doesn't really need. Especially if he is an easier keeper like you previously noted.

I don't think it matters if you blanket them. As long as they have a good coat, good weight, and shelter from wind/rain they'll be fine. Mine go throughout the MN winters just fine without blankets or grain.

The the Alfalfa pellets are the way to go then. They're safe "cool" calories for most horses, and they're readily available.

ADM Ultra-Fiber is a low starch feed that is high in fiber, we pair it with ADM's Metabolic Mineral Pellets and a daily dewormer. My horse has NEVER looked better.

Take a look at Enhance Equine Senior. The price per bag is higher than most on the market but the feed ratio is only 1# per 700# of horse.
It is actually cheaper to feed than a $10.00 bag of sweet feed in most cases.
It's mostly Rice Bran and soybean so you get a great looking coat and the horse doesn't get all sugared up from molases and corn.
Know a thoroughbred trainer at a race track that uses it and ended up saving $1000.00 a month on his feed bill.
The vitamin/mineral ratio is way higher than others also, so you don't have to worry just because you are feeding less your still getting everything you need.

So it looks like the general consensus is something like alfalfa pellets.. Thanks, guys. I'll look into that! =)

MN - I live in Wisconsin, so we're about the same climate. I only blanket him when it's raining and freezing or super windy because he just stands out there and shakes instead of going in the shelter. -headdesk-

Typical. Mine like to stand outside too... Well at least a couple of them do. My old lead mare (she died years ago) wouldn't ever come into shelter. No matter how bad the weather was.. Drove me nuts sometimes. She'd be completely covered in snow or completely wet and wanted nothing to do with the lean to. Weird.

Alot of feed manufacturers are starting to have a line of Lower Starch feeds (starch is what will make your horse "Hot" if they are getting too much in their diet)...I use Front Runner COOL COMMAND. Mcauleys also makes one called ALAM I belive.