Hankook Dynapro ATM is a very well rated high mileage tire that also does decently in the snow. However, true winter tires are far superior in tread design and compound compared to any all weather tire. True winter tires do not have the high mileage rating because of softer compounds - but they're safer and more effective snow and ice tires.
I run Hankook Dynapro ATMs in the summer, and the Hankook iPike in the winters. I live in Colorado and range between highway commutes to the airport, to high country ski trips, to county roads that are not plowed in the winter, and I'm very happy with that set up. The Dynapros are not a high ply tire however, and if I spent significantly more time off-road I would go with a different tire. Bridgestone Blizzak is also an excellent winter tire, however due to the compound you're probably looking at a maximum of 15,000 miles out of them, but probably closer to 10k.
You ultimately have a decision to make about how secure you want to be in winter driving and how often you will really utilize the benefits of a winter tire. If you feel your 4WD is sufficient for your winter driving, then look for a highly rated all season tire.