I'd scratch them off my list of things to have unless I was going to be doing an overwater flight or something like that, and even then there are better options.
In my experience, if you're not wet while wearing a wetsuit, you're sweating. I don't really want to do that, because at night in Wyoming, I'd imagine it'd get pretty cold, and if you're all sweaty, you'd be in trouble then.

As far as packing them up goes, mine's a Farmer John style, and it's anything but compact. Plus, like someone else said, if you've gotta go, it's gotta go. Then you'd REALLY be cold! <img src="/images/graemlins/tongue.gif" alt="" /> <img src="/images/graemlins/blush.gif" alt="" />

If you get wet in a wetsuit, then when it comes off, as it will eventually, you're going to be freezing bigtime. Plus, once the nice, warm, insulating water drains from them, they can get chilly.

Just some thoughts from a cold-hating Florida boy. I've never messed with snow extensively, so you'd know more than me.

Staying warm,
Kyle