Congratulations! As its got colder, Ive had to scramble to order gear as this is my first winter commuting, and just did not get very prepared gear wise I guess. All that to say, I recently placed my socked feet in plastic bags (like grocery store style) and then my shoes over that. This worked great, as the main thing is to keep the wind off, and keep dry. I would only use such a tactic in a pinch however, as this causes you to trap moisture in the bag. Too long a ride, or too many longer rides would likely start to destroy your feet. Or at least cause an extremely unpleasant odor issue. Im hesitant to give a guess at how long would be too long, as everyone perspires at different rates and such. Myself, I wouldnt do more than ten miles in such a setup. Anyhow, it worked awesome that one time, and Ill likely use the idea again at least a few times, for what thats worth...