I agree with kickstarter. Regular boots work great for really cold days and are multipurpose. Also, usually a lot less expensive. If it snows and you end up pushing the bike or walking, a hiking boot is preferable to a cycling boot. I install Shimano M324 pedals on my winter bike when I need to use boots. One side is SPD and the other side has a platform with lots of grip. While I don't like not being clipped in, it's not such a big deal, and you can always get Powerstraps or make your own.