In the Pacific NW coastal areas, it's possible to ride every day of the year; the snow just doesn't fall that often or get that deep, like in the midwest. A fresh snowfall is usually the safest time to ride during that snowfall period, as it usually isn't deep, and the tires easily cut thru the soft snow. Days 2 and 3 get tricky, as the snow gets packed down and icy, or thaws and refreezes, making for treacherous icy spots that are hard enough to toss a front wheel around. This requires a bit more craziness to risk!
Commuting thru the snow has always had the element of elitism in it for me. Only the best, the most skillful, the toughest and hardest, can do this. Those who have to ask why just don't get it. They are the 99% of "normal" people, the fair-weather riders, the uncommitted. Not real cyclists. Sorry if you're in that 99% and offended; that's just the way I feel about it!
But then, at some point, you have to try to balance the "elitism" with the risk, especially as you get older. I'm looking forward to retirement, where I won't have to prove anything anymore, and where I can quit having the impromptu street races with young guys out to prove something! Yeah, it's competitive out there, and riding thru snow is part of the competition!
Luis