If the weather is bad enough, I will take transit instead, but cycling down to -10 C is doable without any problems.
I will be far less inclined to bike if it's raining, that I do hate with a passion. Of course, I could just work from home in that scenario as well, if I don't feel like taking transit
Free cardio, what's not to love? E-bikes are an option for those that don't love it