I have been using George white's 'Craft Manual of North American Indian footwear' since I found it in 1970. He talks you through making the patterns for each type, and most the major moccasin types are covered. I usually make the Salish (Flathead) for myself, which is similar to what you what. For this time of year in Ideeho, get a pair of felt packs, and measure your foot wool socks and them on. I wore canvas Mukluks with felt packs, and wool socks in the Antarctic and never had cold feet. Not much difference between buckskin, and the canvas.....except looks.
Woody