I live in the South western part of the state by west yellowstone and have not personaly been to Kalispell, but here is the website for the Snowmobile club there, I'm sure they will be happy to help you out with everything you need. Montana Snow Measurement Summary Their official website can also be aquired threw this page.
Im not sure if you can ride anywhere before Dec.1 in the Flathead valley. Check on snowest.com in the Montana section for a possible area to ride if your super-eager.
Not sure what your riding ability is, but you cant go wrong with riding the 'Canyon-Creek' ride area. Lots of nice pulls and boondocking with easy access from well groomed trails. If your more hard-core i have heard that a ride area called 'Six-mile' near Big-Fork is pretty gnarly and extreme. No groomed trails and not a cup-cake ride to get to the good stuff. Never been there myself. I like Olney personally as you can get off the trails and explore (and also get lost....) bring a GPS.
Agreed. I don't know what's open up there, now. I've never ridden in Kalispell that early. The snow is usually OK by then, but you never know. Also, it depends on where you want to ride. There are some areas that have giant boulders, and early Dec is too early.