+1 .
I also learned when I had to ride across town to work on winter mornings at temperatures occasionally below 20* that wicking and ventilation are most important, especially if you sweat a lot. I'd get to work with my jersey soaked, tho' the wool still insulated. I quickly found that any shell without ventilation will make you sweat even on a very cold morning, and that layers of wool keep you just as warm and much dryer. Tho' shells are ok for =< 10 miles especially if they have pit zips.
Gloves: very important. I have a stackable system, starting with DeFeet knit wool gloves, then lobster mitts, then a thick nylon shells to fit over everything. I've not had to use more than the wool knits under the lobsters, though.
Feet: 2 thin layers of wool; perhaps plastic bags over socks and under shoes if it gets a bit colder (my feet don't seem to sweat and the plastic does help a bit to block the wind); and for under 30*F, insulated riding shoes. A cheaper alternative which I've tried is a cheap pair of summer cycling shoes a size or 2 big that let you get layers of socks inside, and Shoe Goo smeared over the mesh.
Don't wear tight shoes!
Ears: mine get cold. Baclavas, even better faux-Peruvian wool hats, (with or without tassles), and last winter, a state trooper winter hat out of Fargo, the movie. Thick nylon shell, plush lining, flaps that pull down and fasten under chin, or else velcro up on top.
Getting back to shells: Can anyone recommend a full-zip, high-collar, thick wool knit cycling jacket with sleeves cut long? Not a hoodie or a pullover. If it has pockets in back or on the sides, all the better. Just knit wool, no lining or outer shell.