The higher elevations of Montana could see well over a foot of fresh snow by Friday. Most counties have a storm warning or watch in effect, and the valleys are expected to get 5" to 10" inches as well. Travel may become a serious issues during this storm.
Skiing and riding at resorts is fine, but Tuesday is NOT the day to explore the new snow in the backcountry near Bozeman and other areas of southwest Montana. Avalanche danger is extremely high, and the risk of triggering a huge slide is very real.
Lots of mountain snow is falling in Montana, which is great news. Montana is still very far behind normal average snowpack levels and drought concerns are still big. Towns and valleys can expect some snow, but high elevations across Montana are expecting 4" to 8" of fresh snow, with up to a foot in some locations.
All I can say is, if COSTCO was nearly completely out of these things, I'm assuming you might have trouble finding one of these after that freakish cold snap we just got hit with.