I called my friends at the bike shop and got their advice. They also recommend I go with a winter bike instead of winter wheels. (They know I'm not buying a new bike for this, just a freebie or beater bike. Besides, they are friends so I can trust their advice.)

Serendipitously, someone was asking me for advice for his new bike, and during the conversation revealed that he has a bike, but the seat tube broke, and he was trying to give it away, thinking someone could use it for parts. I have a friend who is a free lance bike mechanic and has welding tools, and when he gets back from holiday traveling he's going to take a look at it and see if it's repairable.

When I picked up the broken seat tube bike, I said in astonishment, "You have an entire fleet in here!" I ended up taking home a 2nd bike as well. It's a heavy walmart shimano mountain bike, but it has disc brakes. Although it being so heavy, after what you said, is a little bit of a concern, I could go ahead & try it out with studded tires--if I don't like it, I can use the studded tires on a different bike. (Both of the freebies are 26" wheels.) But I'll hang on to my current 700 cc studded tires a while longer, in case neither of the freebies work out for me and I end up with winter wheels, or yet another freebie bike that takes that size wheels.

When we first got this snowfall, and I saw the forecast, I thought the roads would be clear after 2-3 days, and other wanting a chance to use my studded tires on snowy streets, it was hardly worth putting them on. However, the 2 warm afternoons were just enough to make it mushy and it's since frozen again, so the streets are actually really awful, with rough, bumpy ice that is unpredictably hard or slushy. I'd be awfully tired of walking by this point, if I hadn't put the studded tires on.

The parking lots are even worse. I dropped by my office this morning briefly, and I hesitated when I reached the worst patch. Instead of plowing right on over it, I put my foot down. My foot slipped. I fought to keep my balance but gravity was inexorable. Eventually I landed! Although my hip hurts a little, my biggest regret is that no one was there to laugh. I'm sure it was a sight!