It's well worth investing in appropriate footware, especially if your going to be in a static situation.
My winter boots are sized to allow for thicker or layered socks. When buying new boots it's best to try them later in the day when your feet are at their largest, tight boots don't help to keep your feet warm.
Winter socks for me are Woolpower Merino, got some different weights so I can layer if required, but my favourites are Dachsteins
It's not been really cold up here this winter so my Sorels have a had a rest and I've been using a pair of the issue ECWW boots with a GoreTex lining, I've been quite impressed with them and they've done the job admiraly.
It been donkeys years since I've had cold feet, been there, done that, never to return.
My sons been using a pair of 10mm Bison neoprene wellies this winter, £50 on eBay IIRC, and he's been well impressed.