https://www.meilimuseum.ch/holzvergaser
a beautiful foto collection from @Holzi from svizzerland…
I’ve never seen chains, but my brother would ride his bicycle year round and bought tires with metal studs (like Bicycle winter tyres - treads and studs explained | BikeGremlin US). He said they helped a lot.
One winter he had a problem. On some days his bicycle performed just fine. Other days, he’d be halfway to work and the hub wouldn’t engage. He finally took it apart but everything looked fine. He put it back together and things worked great…but only for a few days, then the same problem returned.
He eventually took it into the bicycle shop. It seems the grease used freezes when around -20° Fahrenheit (or about -29° Celsius).
The old Sturmey-Archer hubs took oil instead of grease. Makes real sense in cold weather.
The 4-5" wide “fat” bike tires are supposed to be good in snow. They are used a lot in sand. I don’t know if they come studded for the ice as well or not.