Depends on "winter" and what I am doing.

if I am being active, I may use a nylon shell pant over fleece.

More usually I have two weights of wool pants, with suspenders. one is a lighter weight wool, more like a heavy jean made of wool, that works fine in warmer temps or as a top layer. For super cold I have a pair of thick green wool "codet" brand pants that I've had for a while (I think you can get them at Wholesale Sports in alberta chimpac)
These are alway "pants" but I wear them pretty high with suspenders in winter.

While I may wear a parka for short jaunts or just slow wandering, normally I am a layerer, because otherwise I just end up sweating.

The bottom I will usually have on a layer of synthetic long underwear and a pair of wool pants. the top I will again have a syntheic or merino top. then layers of wool sweaters and/or fleece. my usual outer layer is then a homemade cotton anorack made from a red cotton materiel about the weight of heavy jeans, but any amount of that may be put on or pulled off while I am active. I do often take a big poofy parka to lounge in at the end of the day, but almost never wear it while moving around.