I'll chime-in once more with some random thoughts on the "ideal". Anchorage is definitely a challenge for winter commuting, the MUT's are just hilarious after a couple of freeze-thaw cycles and giant carnivorous trucks/suvs rule the roads and can't be bothered with details like bikes or pedestrians especially if they have an important call on the cel. Things are actually a little more friendly in Fairbanks, at least on the west side of town and of course we don't get the ice and slop you do down south.

I ride a cyclocross frame with a single ring up front and 9sp cluster in the rear, studs go on after the first snow and usually don't come off until March. When I was living in Anchorage
(and the first winter here) I was riding an MTB, imho there was really no advantage over the cyclocross set-up, at least not for commuting on snow/ice covered pavement. Suspension components pretty much stop working below 20F and then you are just hauling around some extra weight or worse something that will actually break at some point. Riding position isn't really that much of an issue, on a well fitting MTB your weight isn't distributed that much differently and I think people don't realize that it is important to have some weight on the front wheel. I use bar-end shifters and cross-top (chicken) levers. I lower the seat a little once it snows, I find it helps me when I need to dismount/remount quickly. I used to use "commuter" pedals that were spd on one side and platform on the other but I've reached a point I don't find I need them and now I just run the same shimano m540 spd's year-round.

I find deep snow (more than 5 inches) more of a problem than any other condition. It was no different on the MTB where I was using the widest studded tire I could find at the time, maybe 2.75. Flotation is just not an option, you cut through and if you don't hit bottom you spin or waffle. The "Snowcat" approach is interesting but not very practical for a commuter bike that maybe a couple days later be navigating iced pavement.

This season has been pretty laid back so far, we have had snow for almost 3 weeks but the temps have been above zero, I bike commute to work at least 4 days a week most of the winter. The one thing that really has become apparent to me the last 2 seasons is how inadequate rim brakes are for the winter cyclist. When I was riding the MTB I had mechanical Avid Discs which are still superior to any rim brake I've ever used in snow and rain, they functioned well in extreme temperatures and were reasonably easy to install and maintain. I think if I'm here for another winter I will find a cyclocross frame with disc mounts, probably a Redline Conquest which I've owned before and really enjoyed.

My next thread I will ask the question: "who really needs $200+ bicycle headlights"?