Who has insulated winter shoes?
What shoes do you have?
How cold is it where you ride?
How much more time can you spend riding in that temp. because of your shoes?
How do they fit (relative to anything, like Sidis, like Birkenstocks, like other cycle shoes, or other street shoes)?
Do you also have extra insoles or booties or other tricks up your sleeve (or your sock)?
Anything else?
I'm looking for SPD compatables.
Now that my hands and cheeks are warm, my thoughts turn to my feet.
Who has insulated winter shoes?
I have an older pair of Diadora winter shoes and have used them a great deal. They are SPD compatible, and generally are about a size larger than my regular shoes. Temps here can generally get VERY cold, anwywhere from 30 down to negative temps and windy. If it gets consistently below "zero" I will put regular pedals on my bike and ride with my hiking boots on, otherwise these shoes are pretty good. I put thin wool insoles in mine years ago, like most people in New England do and that definitely helped quite a bit! I also tend to wear Smartwool or similar socks with them. If I'm riding when there is lots of snow, I'll also put gaitors on top... keeps the snow/wind from going down inside the boot.
If you should find that the shoes are not warm enough, you could always buy an extra pair shoe/toe covers. Or as others have recommended, use chemical toe heaters. Although the future is showing us that boots with heating elements (like ski boots) are available as well... although pretty expensive. These same heaters are something that you could purchase and install yourself... so something to think about.
Next pair around, I would more than likely buy either Louis Garneau or Gaerne... both great shoes as well.