I live in MT, go to Japan. Don't get me wrong the snow is great here but Japan is world renown for their low moisture snow and you would be a fool to choose MT over Japan.
the article is a bit nerdy and a bit old and crusty since its coming from first tracks but the figures he drops about the snowfall cannot be questioned
you'll get more than just skiing out of a month in Japan. Im not saying Montana doesn't have culture, its just not gonna compare to what you'll experience in Japan.