Even if you're walking, -20C and below is just too damn cold even if you have proper gear.
That sounds like bad infrastructure, which admittedly is the default almost everywhere.
There's also a safety issue in that if you're in that kind of cold for long enough, it'll kill you, jacket or no jacket.
Again, it's a matter of infrastructure and priorities: https://youtu.be/Uhx-26GfCBU?t=260
> There's also a safety issue in that if you're in that kind of cold for long enough, it'll kill you, jacket or no jacket.
In any situation where being outside for the time a commute could take would kill you, roads wouldn't be safe to be driven on.
However, what if you have a 30-60 min commute and it’s -20, -30 out? You can easily drive that, but cycling is another matter.
Bikes are but a means to an end: decreased traffic, reduced urban pollution and safer streets. Getting more people on bikes means fewer people on cars. Reducing traffic also require good and frequent public transport for both people of reduced mobility and weather events. Most situations were buses or trains are disrupted is a time when driving isn't quite safe either. And cars aren't going to go away, what you want to do is affect the margins: the 2 mile drive to get milk that would 1) ideally not have to be 2 miles and 2) trivially cycleable in safe infrastructure.
I am also of the belief that increased density should be a goal, for multiple reasons, which would make the need of 60 minutes commutes unnecessary for most, with the lovely side-effect that people that desire a suburban lifestyle can still have it and the equation for both bicycles and public transit a no-brainer.