I spent a year living in a survival/outdoor school in Wisconsin. In WI we lived in wig wams, snow caves or just on the ground wrapped in wool blankets. The school didn't allow any synthetic material so we all had to scrounge up wool clothing. After that I worked as a horseback hunting guide in the Uncompaghre Wilderness of CO. Base camp there was 11,000ft and we ran the season from July pack trips through August/Sep archery all the way to getting snowed out in the late rifle seasons. After that hunting season I stayed out there and was a Ski Instructor at Telluride. My Marine Corps Reserve unit specialized in Cold Weather and Mountaineering. We did trips to the Sierras, Minnesota, and Northern Norway above the Arctic Circle. So, I feel like I've had some experience in harsh environments with varying levels of self sufficiency and here are some things I learned from that:
1) Smartwool is expensive as hell but it's the greatest base layer I've ever worn in my life. Much better than any polypro or synthetics that I've warn. It's not too hot, not too cold, it's the Goldilocks of base layers and it's worth every penny. I now work in the oilfield and the only socks I wear year round from Texas to North Dakota are smartwool socks. I'm a zealot for this stuff and encourage it wholeheartedly.
2) Ebay was a great resource for used wool clothing. I got a bunch of Pendleton gear there for low prices.
3) Salvation army, Goodwill etc... are also awesome resources.
4) Old military items are decent especially as an outer layer. Here is a link to the type of trousers I wore all year in WI and Colorado. Only 15$ plus shipping!
http://tinyurl.com/y6gblu4p
5) Overall I've found that older plain wool clothes are superior to new synthetics especially when comparing cost, versatility, retaining body odors, and comfort.
Do you have an idea of what the hunting is like? I suppose it will be a mix of stalking and glassing with some days heavy on activity and others (especially towards the end of the week LOL) that are more lazy. The Russel gear looks pretty good. How much of that do you have and how many/what layers?
Your Montana hunt sounds awesome! Hope you have a good one and post some pics afterwards.