My bikes are my transportation. I ride straight through the winter, although I do reduce the number and miles of recreational rides. I try to compensate for reduced miles with floor exercises at home. I'm in a third-floor apartment so trainers and rollers are out of the question.
I also don't subscribe to the "get an old beater bike" strategy. I like cycling too much to waste my time riding some one else's cast-off POS.
Is the Trek 1.1 in your sig is your only bike? It won't fit studded snow tires, so you'll have to choose between getting an old POS or getting a new cross bike that will fit studded snow tires.
When I upgraded my commuter, I went with a Trek Portland because it hit all my bullet points for a four-seasons, all-conditions bike. As pertains to winter, it has disc brakes and room in the frame and fork for my Nokia Hakkapeliitta W106 studded snow tires with fenders. I ride this bike year-round, although in the three seasons it gets an occasional rest since I use my other bikes then too.
You'll hear all sorts of stuff about increased wear and tear instantly ruining bikes ridden in the winter. That has not been my experience. In three years of winter riding on this bike, the only component I've replaced where winter riding was a direct cause of failure was my rear brake caliper. It's nearly impossible to flush out the salt, and corrosion seized the adjusters. The front caliper is mounted vertically and is easy to flush out after a ride.
I've installed a hook in the bathtub to hang the bike so I can rinse it down with the handheld shower. I do this after every wet or salty ride. That limits wear and tear to the chain. I never get past March without replacing the chain. Although I got only 11,000 miles out of my middle chainring. I use a different cassette in the winter for different gear ratios. I'm still on the same winter cassette, three years running.
Before buying this bike I had issues with excessive brake wear. Brake pads wear much more quickly and I wore out the braking surface on a cheap set of rims.
I do ride my pure roadies in the winter, but only on days with relatively clear roads. They're all equipped with fenders. My Trek 1000 (forerunner of the 1.1) wears SKS P-35 fenders. They may fit your 1.1 too.
I replaced the factory "fenderettes" on the Portland with full fenders. I use the "fenderettes" on my other road bikes. This year I'm going to try out the
Crud Roadracer fenders on my Litespeed. I'll report back in spring.
Finally, as others have said, avoid the knee-jerk impulse to bundle up when riding. You'll be making plenty of your own heat. In winter, just as in summer, sweat management is my biggest clothing issue. The only difference is that in winter, it can lead to hypothermia.