I used to ride in the cold with a full face helmet and a ski jacket that was made with hollow fibers. It had a high collar. The cold did not penetrate that jacket at all. I still have that jacket but, alas, it must have shrunk over the years because I can't zip it up now.
Currently, I have a heavy coat that I wore when I worked in Wisconsin. that and a full face helmet will keep my upper body warm except for my hands. Leather chaps for the legs might work.