tsl and I have a fair bit in common in that we commute / ride daily and don't think that a person has to ride a second rate bike just because the weather and conditions suck... winter is too long here to ride a crappy bike.
This does not mean you have to spend a fortune on any bicycle but if a bike is going to be subjected to harsher conditions it may very well need to be the nicer bicycle.
My new winter bike is not really new as I used an NOS frame and the wheelset from my old winter bike which was retired from winter duty to serve me as a commuter / trekking / utility bike through the 6 nicer months of the year.
I use two bikes in the winter... both are mid range Norco models and the ice / apocalypse bike has an internal gear hub and studded tyres while the extra bike is remarkably stable without studs and is derailleur geared which actually lets this heavier bike roll out a little faster and it is capable of handling things like grocery shopping without needing a trailer.
The extra bike runs slicks in the summer and I also have a studded tyre mounted on it's own wheel that I can swap in and out as I need it.
The benefit of the IGH is that it will run smoothly at temperatures < -40C as it uses synthetic oil as a lubricant and does not lose efficiency.
The derailleur drive on my extrabike has been very reliable in all but the coldest of weather but did get a little skippy when I was riding at -46C...