I've had my eye on a different version of these for a few seasons, but a combination of injury, laziness, and forgetfulness kept it such that I only remembered when actually out riding in the cold and wet - which was less frequently in the past year+.
I've run pogies on the moto in the winter (back when I used to commute year round on it) and the combination of a heated vest and pogies made all the difference in the world. They look dorky as hell, but you've seen my fender... ;p
I'm not sure how much protection those handguards that some of the EWS guys use would give you from the cold. I asked Jesse about them when he was standing in line behind me at Whistler at the beginning of last season, and he said he was "just trying them out" as some of those Euro courses are super tight and he hits a lot of branches, etc. (same reason many of those folk run narrower bars than one might expect). Seems he liked them as he's been running them for a couple of seasons now.
In terms of pinkie protection, I really like the LoamLabs Counterpunch. I bought a pair after clipping the rock wall taking the high line on Pamplemousse, but they stayed on my workbench for a year. I finally installed them on the DH bike this past season and liked them so much that now I run them on several bikes. They won't help one bit with the cold, of course, but I've glanced off enough trees with sufficient force to be fairly confident that they've saved me some bruising for sure, if not a hairline fracture or worse. They actually help with control as well you can run slightly a looser grip and the Counterpunch helps to keep your hand in place, and gives you a bit more leverage when needed. I'm a big fan.