Seems like everyone's missed the number 1 best option: LEARN HOW TO DRIVE IN SNOW. In my opinion, succesfull driving in snow depends on the following factors in the order presented:
1 - Knowing how to drive in snow, ice, slush
2 - Tires, as that is what's in contact with the snow, 4x4 and AWD doesn't help if you don't have traction with your tires
3 - Traction Control - most all cars have it now
4 - 4x4 or AWD
Personally, I've never used studded tires, so can't really comment on their effectiveness. I never felt like I needed studded tires (PNW) and I find the clicking really annoying on dry roads when someone drives by, plus, they chew up the roads.
Chains - I carry them because they are required (to be carried) on the mountain passes in the PNW between November and April. Although living here for 17 years, and driving the passes 60+ winter days per year for the past 7 years, I have never actually used them. I've purchased chains for 5 cars and they all remain in their box, never used. The DOT in the PNW will specify if chains are 'required' but in my experience, if you have AWD or 4x4 with 'Traction Tires' than you usually are exempt from the chain requirement. Not sure what they do in the lovely state of MT.
My favorite All Season tire, which performs better than many snow tires on the market, and really are in a class by themselves for a snow biased All Season Tire is the Nokian WR G2 SUV. They've recently discontinued the G2 and are now G3 (Generation 3). I read one review that said G3's aren't as good as the G2's were in snow and ice, but still the best out there for an All Season. I highly recommend Nokian WR G2's.
As far as learning how to drive in snow: At some point, you need to find a nice big parking lot, full of snow, ice, etc (careful of curb islands and light poles !!!) Than go for it ! You really have to get the vehicle sliding all over the place to get a feel for how it handles, and what the limits are to stay in control. Just make sure there are no people, vehicles or other obstacles that can cause you or others injury or damage. Getting the vehicle to slide 'a few feet' isn't going to help much in my opinion, you really need to find out what happens when you're going way to fast for the turns, braking, etc - than ease everything down to a point you can drive without any sliding whatsoever. The next thing is learning how to drive to never get stuck in snow - 90% of people stuck in snow, spinning their wheels are because they don't know how to drive in snow (again, just my opinion), and they can easily 'unstick' themselves without leaving their vehicle, without shoveling kitty litter, etc. but that's a whole other topic, and a few interesting facts about 'how' snow / traction tires are designed to work, that is counter intuitive to what most people think.
Enough of my blabbering - enjoy Montana - I've just visited briefly - seems like an awesome place.