I've no experience with winter cycling shoes or boots. They seem to be rare, so I'll also be interested in reading anyone's comments about how they work out. Ones I've seen, look like they'd be good for Alaska or Minnesota, but here, I don't know.
Shoe covers, or 'booties' have been a godsend for me. Wore em today. They're hard to put on, but only because I'm jammin' em over a pair of mountain shoes...model mountain shoe I have is essentially just the same as an economically priced road shoe...$80-$90, but with the lugged sole. Booties slip right over the road shoe I have. Booties are the Louis Garneau line from Performance, neoprene.
Unfortunately they're sized rather small. The XL fits over my sz 45/10.5 mountain or road shoes, but I think that's the limit. The wear issue is a concern, but unless walking around on them, it's just the 'toe-down' foot for stopping that's gonna get much wear. After some use, I just decided to cut out a piece of inner tube and shoe-glu it onto the toe. Works great.
Feet getting cold: Since I started being less concerned about maintaining 'cycle-chic', simple improvised solutions occasionally come to mind. I eventually figured out it wasn't the part of my foot in the shoe that tended to get cold near as the part of my lower leg around my ankle that was particularly susceptible to wind chill. Funky solution: cut off tops of heavy wool hiking socks whose soles have gone by the wayside. Put those on over the ankle part of the cycling socks. Then, like today, with the booties too, I'm toasty. When it's dry, not too cold, I just wear the anklets. Whole Earth Daddy look.