It does get a little brisk at times out there. Grow a beard too if you are looking to save cash. That way you don't have to buy protection for your face on sub 0 days.
Thermals, wool socks and a sweatshirt are the most widely used combo as base layers. I will never own anything but airblaster ninja suit for thermals. It's a one piece suit so no snow down the back and it has a hood and an ass zip so you can poo without taking it all off