When actively moving around in the bush in winter, don't find a down parka cuts it.
I layer and layer and layer. I'm very fond of multiple layers of wool, not necessarily
one heavy wool sweater. Typically I'm looking at poly long johns and wool pants,
then a light poly undewear top, with a merino shirt or two over it, a cashemere thrift
store sweater, maybe a fleece, (or two) and a top layer, like a homemade anorak or
a primaloft jacket - not warm enough on it's own, but a great windcutting warmth adding
outer layer.

I really like my nice 800 fill parka to climb into in camp, but it's not a moving around
outside doing things kind of parka.