>>692306They are wearing traditional cotton anoraks.
Cotton anoraks with fur hoods are preferable by many in dry cool conditions because they cut wind but also allow moisture to escape. No matter how much "breath-ability" a shell says it offers at a certain point the moisture you build up from sweating is too much.
I don't know about you but I've owned several shells from north face to mountain hardware to arcterx and I roast if I have to do any substantial physical activity.
With serious winter camping expeditions layering is key just like any other time of the year preferably with wool. A big insulated parka is out of the question because most people will sweat doing anything remotely physical with them on, however, they are often packed on toboggans for use at camp or when ice fishing.
This is a great article about cotton anoraks:
http://wintertrekking.com/clothing/outerlayers/