My favorite things for winter biking are in this order

- My Surly Moonlander - ok it's not exactly mandatory but it sure is fun! I'll commute on it when it's snowing.
- Having proper clothing and knowing your options for different conditions - this takes some trial and error (take notes) it is huge factor in long term success
- Studded tires. On my main commuter, Cross Check, For me they make it daily riding possible and much safer.
- Reliable and bright lights with back ups. It's dark as hell out there when the days get short, the roads are sketchy, it's good to see where you're going and be seen.
- Winter boots, I got the 45NRTH boots last year and they are stupid expensive, but they work.
- IGH - I like gears in the winter and the IGH is easiest to maintain.
- Fenders - not a deal breaker, but they can keep you and your bike a little more clean and dry.

Disc brakes are nice but not at all critical. Get some Kool stop salmon pads for the non disc brakes that you do have. They are the best for winter.

Rest assured, Winter WILL take it's toll on your bikes. Lube everything well before the season starts, including your seat post. Try to keep the bike semi clean, car wax on the frame helps repel some of it. And definitely keep the drivetrain well lubed it's easier said than done sometimes. PLan to replace your chain every spring.