I did the Highwood 300 a couple years ago with the Alberta Randonneurs; great ride!
Last weekend, I was out near the road closure (but not past it). The shoulders aren't swept (yet; surprise, surprise) but the road was perfectly clear the whole way to the closure. I imagine it is also dry up-and-over (maybe some wet patches, but I don't think you'll encounter any snow).
The sheep herd up there is pretty used to people, so while most sheep run away as a cyclist approaches, I find that the herd near the top of the pass doesn't. Count yourself lucky if you see anything else large-animal-wise
Couple pics here:
http://www.flickr.com/photos/mike-wa...756912/detail/