I live in a rainy but not snowy place, so take this with a grain of (non road) salt, but I just use a rain shell (pants, gloves, jacket) and then a fleece under that. Sometimes a second fleece if it's going to be bitching cold.
This is what I use also in a wet and mildly cold (rarely below freezing) area, except I never bother with the rain pants. I find they cause me to sweat too much to be useful.
My core warms up a fair bit from biking, so the only thing that bothers me is cold fingers. I found simple thin gloves work most of the time, and use thin glove liners for December/January.
I commute year round on my bicycle and have done so for years.
Generally once the weather goes below 0°C I start with the toque and start wearing long underwear beneath my jeans. Throw a windbreaker over a sweater like jacket. I will throw some wool gloves over my regular cool weather riding gloves as well.
Once the weather gets in the range of -5°C or colder the balaclava comes out and thicker winter gloves. Wear a proper winter jacket and water proof slip on pants over the jeans. Also keep a pair of snowboarding goggles in my bag in case of very snowy weather. Would also recommend waterproof footwear of somekind when snow and slush begin to show up.
Definetly trying to scrape some ideas from reading this thread myself. I don't want to bring a pair of waterproof foot wear if I can help it. So I'm reading through here to see if I can spot anything useful for that effort. The fogging goggles is another thing that could be improved on for those particularly nasty snow days.
Car or candle wax worked for my glasses in blizzards. I tried those booties that slip over your shoes for wet/snow riding. They're effective, but you put holes in them as they're effectively thick plastic bags with zippers.
For real cold, wet rides: neoprene socks. Your feet stay warm and dry, but your shoes won't.
I have lots because Colorado falls are roller coasters with temp.
On "warm" 50⁰ days, I'm usually do a base layer of a Nike pro lycra shirt and shorts, then typical jersey and shorts with arm and knee warmers.
On cooler days, same bases, but with a warmer jersey and maybe fleece knickers or tights. The fleece cycling gear is always smaller than the summer gear and stretches less as well, so I find it very uncomfortable. Maybe lycra booties, ear warmer and comfy gloves (love the head gloves from Costco).
If I'm crazy and it's under 20⁰, then a very warm capo jacket over a long sleeve base layer and 2 layers of tights sandwiching my shorts (or a unique pair of pearl izumi wind proof tights), warm pearl gloves, warm hat and neoprene booties. If I'm lucky, I'll last an hour.
Greatcoats actually work well on a bike when it starts to get pretty cold (ca. -20°C), I have a thick wool one that is Russian navy surplus and I might look like I just biked off of a warship, but it keeps me warm yet also breathes if I get too warm. Also, it's long but splits down the middle nicely when I straddle my bike.
I haven't biked in much colder than that, though in the winter it easily gets to -30 to -40 here. I kinda want to try but it's quite intimidating both in terms of keeping all my extremeties as well as all the ice.
Snowboarder jackets are great for city life and winter biking because you can get one that looks reasonable fashionable to your standards, they are warm and wind/rain/snow proof, snow lock that keeps cold winds out, and generally functional with zippers to vent body heat and humidity and lots of pockets and whatnot.
Also rain chaps that protect your thighs and shins from rain and fold up small into a pocket of the aforementioned jacket.
Oh yeah! Nokia winter tires with studs. Makes a world of difference in Scandinavian winter. I could easily plow through half a meter of ice and snow on my old city bike without worries. Not cheap but they will last many many many seasons.
I tend to run pretty hot, so it doesn't take much for me to stay warm so if I'm going to be active outside in the cold weather, whether it's hiking, biking, or the rare occasion I get it into my head that I'm going to try running/jogging, usually I'll throw on some under armor and then something lightweight over top so that I'm not that fat weirdo running around in skintight spandex. It might even just be shorts and a sleeveless shirt over the base layer to hide any obscene or unsightly bulges.
Then usually gloves, a hat, warm socks, and if it's really frigid out, a bandana over my nose and mouth to warm up/humidify the air I'm breathing a bit.
Then I'll bring a jacket with me for when I'm finished or taking a break.
I have my long neck/sleeve undershirt I stole from my time in Finnish military service I often put under a T-shirt. It looks kinda wonky but it's really good
I read “cold weather gear” as in gear ratio. As in maybe a little lower so as to increases cadence and heart rate to warm you up a little. On the other hand, I’ve found larger gear ratios to be useful on ice to reduce slipping on acceleration.
I've tried Gerbing gloves, but they're just not working for me; I keep blowing fuses. I'm going to try Hippo Hands and heated grips this year (...but I need longer clip-ons for the heated grips; I think that they're intended more for adventure bikes). I typically have a Klim balaclava under my helmet which is mostly good enough. Pinlock inserts are fantastic when you can get them to seal correctly; I've considered using clear silicone caulk to ensure a good (albeit permanent) seal. I'll wear a hoody under my jacket, and insulated tights under my pants, and a decent pair of wool hiking socks in my boots. (Oh, and waterproof boots are def. better in the winter.) Finall, I put Fly Racing rain gear on over my regularly riding gear, and that keeps the wind off well enough that I can make my ride to and from work down to about 20F without being too cold at 80, 85mph.
Used to wear a very thin yet insulating reflective over jacket, a snood, and a scarf inside. I lost it can't afford another so it's heavy coat time again.
Lands end squall coat, long underwear when it’s super cold. The coat kinda took a dive in quality recently but still a nice light water resistant coat. Showers pass balaclava. Over glasses clear safety goggles when super cold. Used to commute year round in Boston but not so much anymore #HybridWork
Good winter cycling shoes and Sealskin socks. Long windproof cycling pants. Gore and Pearl Izumi are my preferred brands. A long sleeved jersey and a good windproof, breathable jacket. Those can get pricey but it really makes the difference between being comfortable and being miserable. When it gets really cold, I'll wear a thin fleece under the jacket.