My best advice, go to a sporting goods store and save a ton of $.
I paid $120 for boarding pants and 2 pairs of fleece liners 3 seasons ago and they are still rocking. Not only that but they make my @ss look hot, according to my lovely wife anyhow. Plus I don't look like a walking billboard for KLIM or HMK.
I would have been happy with water resistant. If I ever get stranded in the desert I hope to have a pair of HMK boots on as I am fairly certain they actually CREATE water.
Most of the moisture in the boot is created by you. The correct socks make all of the difference. Cotton is a no no. So I guess what you said is correct. They are rated for -50F. I have never been cold in my HMK Pro's even at -5F. I was damp/wet/whatever you want to call it. I have yet to find a boot like a snowboard style that is waterproof. In any industry. It looks like they listened to people though as they have introduced a waterproof/breathable snowmobile boot for this coming year.