And another thing
Please note that "You should get an upright bike with fenders, mudguards, and a fully encased chain or a belt drive, which is more suitable for winter" is not an acceptable solution for many people. All they will hear is "blah blah blah $$$yet another bike$$$ blah blah blah," and then they will stop listening, and that will be the end of winter cycling for them.
You see, many n00bs, especially brokeass n00bs, consider that they have already gone through quite enough time, trouble, and/or expense to acquire a bicycle, so now that the weather officially sucks, what they really want to know is how best to modify and utilize the bicycle that they already have. Everything else is probably just a bunch of lecturing from elite cyclists who aren't in touch with regular folks, even those elite cyclists who actually consider themselves to be regular folks. (Regular folks don't use phrases like "fully encased chain or belt drive" in regular conversation.)
As for me, I'm a n00b to riding the Cross-Check in winter, and I'm too brokeass to afford a Dutch-style bike durable enough to stand up to daily use without falling into a heap of rust by mid-March, so what I need to figure out is how to get the fenders to actually fend away all the filthy slush that's currently melting all over the floor. I'm wondering now if they're trapping more snow than they keep off.