Congrats both of you! I love biking in the colder weather, it's amazing what you can get used to.
Yep rim brakes aren't great in wet cold weather - like an active snow storm. But they usually work the rest of the time. I miss my disc brakes. Using legs to stop, and as ballasts in the ice can work great.
Winter biking requires some creativity, both in what to wear and how to go about it. Conditions can vary alot from cold and dry, to very wet heavy slushy snirty stuff, to just plain slick ice - my route actually varies base on the conditions, and there is some skill involved, it took me at least a winter to feel comfortable biking in somewhat deep snow. The lighter stuff is nicer than the heavier stuff. When it's dry or just icy I take my regular route (but I have studs, so icy isn't really that slippery), when it's a lot of new snow I might take the major road that's plowed and has two lanes so cars can pass easily - usually they are going so slow that I can keep up in really bad conditions - and everyone gives you lots of space, like you'll slip under their tires if the blink. If it's slushy/melty or lighter new snow I take a longer route with a lot of alleys, and connect with a plowed bike path.
I've now biked in my winter boots, and an extra sweater under my shell... I've forgotten how much hungrier you get in the winter. I'm so grateful to my hindu coworker who keeps bringing samosa's for Diwali. Between the heavier boots, the increased snow resistance and the cold it's a calorie burning workout.