An excellant pair of “Pac” boots that I use when it is very very cold are Sorrels, they are a little pricey but well worth it. They have soft leather uppers and galvanized rubber lowers. They are triple stitched, with a bobbed sole. Good traction, and they keep you very warm.
A friend uses what are called Mickey Mouse boots, they are also a “pac” boot. They are army issue, you can pick them up at most army surplus stores. He tells me they have a valve were you put air in which forms to your foot and gives a dead air space, I think he said they are rated to 80 below.
A good hand muff with disposable 12 hour hand warmers works great, I use rag wool gloves they have the tips of the fingers cut off so you can work with them. They have a flap sewed on that when open is attached to velcro, when you detach the flap they cover your fingers. This flap also is just the right size for putting a dispoable had warmer packet in. They work great for the very coldest temps.