This has been a mild winter and to my surprise I'm still riding my bike. In fact, on New Years Day I pedaled to the top of the Appalachian Gap and then back home--not something you'd ever expect to do in January.
When I lived in Boston I rode year 'round. Since I biked to work every day my ability to dial in what clothing to wear could be adjusted with small changes day-t0-day. These days I am a little less able to intuitively "know" what to wear on a chilly, cold, or really cold day.
Its been ranging from the twenties up through the thirties the last few weeks and I've found I can be pretty comfortable on my bike right down through the mid-twenties. I haven't tried biking in anything colder, at least not recently.
One weak point has been --you guessed it-- my toes. In hindsight, I should have relied on previous experience sooner, but for whatever reason, I've been lacking the imagination to try out different solutions.
My typical warm weather shoe on the bike tends to be a pair of Converse sneakers. They are great for many reasons, and recently I've been reluctant to give them up when the weather gets cold. To counter the cold I've been doubling up on the socks and then donning a pair of neoprene booties. I'd say this has worked somewhere in the range of poor-to-moderate.
Back in my Boston commuting days what I did was wear a pair of roomy slip-on loafer-ish leather shoes that allowed for a couple of thick pairs of socks without constricting my feet at all. I found this worked extremely well and the shoes passed as office-acceptable so I was good to go from bike to work.
I have a pair of similar shoes and last night I decided to try my old method. Wallah! It worked great and I was completely comfortable for the seven or eight mile ride home in the dark with temps around 26 degrees.
Beyond the question of feet, I wear two thin long sleeve wool undershirts, a sweater over that, and then always have my plastic neon yellow shell. I love wearing knickers and last night had my Ibex knickers with long thick knee socks and then a pair of corduroy knickers over those. If it were to be a longer or more serious ride, I would have had wool instead of corduroy but these worked fine last night.
Another experiment has been wearing a ski helmet and goggles.
With respect to the goggles, I didn't know my face could be so comfortable. It is though your face is in a small climate controlled room looking out on the world. The downsides were the tinted lens and the perspiration that built up as I climbed the hill out of the village. Also, I find they limit my ability to glance back over my shoulder to see if a car is coming since the walls of the goggles block that sight line. Regardless, the goggles are a definite thumbs-up.
The helmet is fun, and works well with the goggles, but seems not quite as versatile as a standard bike helmet with a hat underneath. Ski helmets are meant to keep people warm who are not necessarily generating a lot of heat and I sense it would be easy to get too warm with the helmet. It does have removable vent covers and ear flaps, so maybe taking those out and putting on a hat would be a good solution.
Its been a thrill to be able to bike right up through the fall and into winter!