I grew up in Missouri and I've lived in Minnesota for the last thirty years. I think studded tires are more necessary in the former (unless, of course, plows polish the snow down into hardpack). Advice above is good. I would actually be more detailed about clothing than the bike. Any decent old MTB would work. I use Boeshield T9 year round as my drivetrain lube. The best thing about T9 is that it avoids rust. After a fall and winter of hard riding and commuting through snow and salt on my fatbike (which I store, with my other bikes, in an unheated garage. I know people say you should store your bike indoors, but those people are probably not married...) I got around two weeks ago to giving it a good cleaning with Odorless Mineral Spirits. There was not a speck of rust on anythibng. Boeshield is gold. So, lube, tires as fat as you can fit at low pressure, and ride.