Not sure how cold you get, but the following worked for me just this past weekend at 18° with a single digit realfeel.
First, use antiperspirant on your feet.
Wear a thin dress sock or liner sock.
Wear a good wool sock.
Regular old tingley boots.
Make sure you're really warm on your torso and head.
Your feet won't be "warm" but they won't be hurting and going numb. Keeping them dry and preventing your body from deciding to pull blood from your extremities to keep your core temp up has worked for me.