Traditionally cotton has been used for the outerlayer and is still the best in dry-cold conditions (0°F and below) and cotton breathes better than synthetics. When tightly woven it's excellent at wind breaking. Sir Wilfred Thomason Grenfell, a medical missionary to Newfoundland and Labrador said "you could not keep a statue warm by putting a fur coat on it. - Clothing must be windproof but must breathe." so Walter Haythornthwaite created for him a 600 thread-per-inch woven Egyptian cotton fabric named "Grenfell Cloth":

Today it's harder to find winter clothing made of cotton. There is Ventile which seems like the modern version of Grenfell cloth but it's very expensive. I also found this site: http://www.empirecanvasworks.com/arcticanorak.htm but I have no experience with them.

The military use cotton in their BDU to make them more silent. They also blended cotton with nylon for a better wind breaker. The famous fishtail parka from the Korean war is an example. It was made of 80% cotton, 20% nylon. Just before the Gore-Tex revolution, Sierra Designs created their 60/40 Mountain Parka which was about 60% cotton, 40% nylon.

Frankie