Interesting that the Michelin All Season is such a good snow and ice tire. Most all season are not. The Michelin must have a superior design, as it's all about the rubber and the pattern and the sipes, and Michelin has been at it a very long time. Most brands, get a winter tire, with sipes now, there is no excuse not to. All Season is some kind of misrepresentation to the consumer.
Another angle on this. Consider your impact on the community, people living around the ski area, skiers and non-skiers, me for example. You have decided that it's not worth your time or money to invest in an extra set of wheels with appropriate tires, (even though you participate in one of the most expensive sports/vacations). It's no longer about averages and likelihoods. This is the big storm and it's going to shake out every weakness in the system. One guy does a 360 on the highway and could easily have killed an entire family coming the other way. Another guy is stuck sideways on the road and has it blocked. No one is getting to the mountain and traffic is stopped, piling up, and waiting. Another guy has waited until he can make no further forward progress and is putting on chains on the side of the road where there is no space to put on chains and everyone going by is in danger of running over his legs or driving into the oncoming lane. Another guy can't get out of the driveway after spending 5K to be skiing, and his kids are devastated. One guy has chains on that don't fit great and he is driving at about 15 mph all the way to the mountain, adding a good 20 minutes to the drive for everyone. Another guy put his chains on the rear tires of a FWD car. It goes on and on, trust me, every one of these things happens every year, I've personally seen it all.
Funny thing. All I have to do (Rockin' Blizzaks, AWD) to avoid these horribly inconsiderate, unsafe and ignorant, stingy and lazy people is to get up a half hour earlier and drive to the mountain when all the locals and employees do. The traffic is fun then, good speed, good control, performance driving, swift and skillful, everyone smiling and getting to the mountain safe and early, coffee in the holder, and rock 'n roll on the 8 track. What does that tell you? People with crappy tires are NOT serious about their skiing.
Buy the damn tires! Rant over.