Much as I remembered, I found fogging/frosting lenses to be the biggest challenge. I wear shades with a clear polycarbonate lens that wraps from temple to temple and covers the bridge of my nose. They have prescription inserts that ride inside of the outer lens. The wrap-around lens protects the bridge of my nose and keeps my eyes from watering due to the frigid wind. I used anti-fog eyeglass cleaner on both the inner and outer lenses before getting on the bike. With a silk balaclava rolled up at the bottom to avoid covering my mouth, I had a fighting chance of keeping my breath from fogging the lenses. Past experience had taught that fog condenses on lenses when I stop moving, and that it freezes onto the lenses quickly when riding in such cold weather.
The balaclava kept my nose and cheeks warm enough, but interfered with my breath enough to cause my right lens to fog at the first stop sign. From that point on, I exhaled by blowing forcefully away from my face. That, along with a crosswind, helped to keep my left lens clear.
As for keeping hands and feet warm, I offer this advice: Start Warm and Ride Hard. When core body temperature drops below a threshold (which differs from person to person), the body reduces circulation to the extremities in order to conserve blood flow to the brain and internal organs. This means cold hands and feet. My threshold temperature is pretty high. Even when I feel comfortable overall, my hands and feet get cold. To ride on cold days, I put on my head covering (balaclava or helmet liner) and my outer layers 15 or 20 minutes before heading out the door. This makes me toasty - perhaps even overly warm - and ensures that my hands are warm when I put them into the gloves. Even so, I need insulated mittens over my gloves for weather below about 28F. Mittens over gloves means I can't grip small objects. In other words, I need to pull off cleat covers, buckle helmet, tighten shoes, etc. before going outside. That's tough if the bicycle is outside in an unheated garage!
Riding hard keeps my core temperature high. Often, my hands will start warm, get cold within a mile or so, and then warm again after about 3 miles of fairly hard riding. I have had little difficulty keeping my feet warm on 5-mile commuting rides since I began using neoprene shoe covers over my riding shoes. I have not found an equally good solution for keeping my feet warm when riding in ordinary walking shoes, which are too wide to fit inside cycling shoe covers. With shoe covers and riding shoes, I wear a single pair of calf-length wool blend ski socks.
This morning, I rode into the office at 14 F. After riding at zero on Friday, it felt remarkably comfortable. With the snow over the past couple of days, though, I needed to walk my bicycle over icy spots on neighborhood streets before riding on the salted main roads.
I'll end by disagreeing with one common piece of winter commuting advice. Don't bother dressing in layers, except to get to your own personal comfort level in the given temperature. On a short ride at low temperature, you don't want to stop to remove a layer, especially if that requires taking off mittens to adjust or stow a piece of clothing. Instead, wear outer layers with zippers or velcro that allow you to adjust how much air gets inside. While stopped at a light, or while coasting on a low-traffic stretch of road, you can easily loosen a velcro-fastened cuff or open an underarm zipper or front zipper. This is much more practical than taking off your outer layer, let alone removing an inner layer. If you need to add warmth during a winter commute and you already have your zippers closed, pull a bandana or short scarf around your face or neck. Never ride while wearing a scarf long enough to get caught in your spokes!
Layering makes good sense on rides over 10 miles long in weather above freezing. You dress for the starting temperature and stop on the road to add or remove clothing to suit the changing conditions. During most commuting rides, you will get to work before the temperature changes by more than 2 degrees.