Goggles are a must for frigid temps. As far as feet go. I'm still experimenting with that problem. Look up Vapor barrier liner for your feet. I'm using bread bags in between the socks right now. Seems to work in the mild temps we're having now. Low 20's.
Recently I've found these.
http://www.rbhdesigns.com/product/34...lated-sock.htm
Maybe I'll try them next year. I'll wait for more reviews on them
Where I'm at we mostly deal with single digits and a few days/weeks below 0f. So I'm looking at better boots now.

"No boot, no matter what the manufacturer's claims, is waterproof when it comes to the varying conditions in the Adirondacks. Frozen boots = frozen feet. Therefore for overnight backpacking sections, removable boot liners are mandatory, no exceptions. Removable liners allow boots to be field dried at best and kept from freezing solid at worst. Also, do not confuse a removable midsole for a removable liner.
VBL sock liners (see below for details) are strongly recommended for all sections and are required for over night backpacking sections. They can be difficult to find. In a pinch, a pair of bread loaf bags (2-per foot, per day) will work. Many of us with years of experience have come to realize that even the best of VBLs eventually delaminate and leak so many of us use both the VBL and the bread bags, or two bread bags together. They are worn between your inner and outer socks. They work. Trust us. "
Ref. http://winterschool.org/faqs.html#8