i've mentioned this before, but the absolute best thing for keeping your feet warm is neoprene diving socks.
even when soaking wet your feet will stay warm, as the water will warm up, just like a wetsuit works.
i've climbed towers in extreme cold weather, snow, sleet, freezing rain, wind, etc, and sometimes you're hanging in your belt for hours ata time, with no real body movement to keep warm, and the worst is your feet are resting on frozen steel tower members, or worse, becoming part of them as the ice takes over.
thing i've found that works is diving socks. here's an example:
NRS Neoprene Wet Socks Kayaking Booties
the same goes for your hands, too. get a pair of 2mm diving gloves and you'll be amazed. thin enough to light a smoke yet nice and toasty.
now that i've done my good deed for your poor freezing bast**ds, i gotta go riding. it's gonna be in the mid 70's today near the beach...