I find wind stopper clothing to actually not perform as well as more breathable stuff. Probably it's to do with how much sweat is trapped and then cools next to your skin. If you were not being very active then I'm positive it would be great however. Also don't forget that if it is too tight then it wont trap as much warm air as if it is slightly baggy. Try losing a pair of socks and see if you feel any difference.
In a similar thread from that other forum (linky) somebody mentioned that it's important to keep your core temperature up amongst other things. http://www.roadbikerider.com/warmfeet.htm
Which sounds like a good excuse to stop for a hot cup of tea and some cake
I am riding with 4 pairs of woollen socks and overshoes at the moment and my feet are still cold! The plastic bag thing works, but it's a pain getting them on under the overshoes and then cutting a hole so the cleats poke through.Surely there must be some waterproof, warm overshoes out there which are also walkable and available in larger sizes??????
I spied some thermal windproof motorbike socks my mum bought as a xmas present for my bro. so I won't know what brand they are till xmas, but they looked damn warm. when i do find out what they are i'll let you know (and probably get some for m yself)