I am remembering more from last year than just that stuck train on Stevens Pass. I was reserved on an eastbound EB that week, and it was many days before they ran through again. I ended up heading out on the CZ and getting to my destination, but meanwhile...
Most of the EB equipment ended up on the west coast, as two trainsets were already west of Montana when they closed all the Cascade passes. A third trainset made it through Montana westbound, and then they closed Marias Pass. They didn't have much equipment left in CHI. I think when they finally got them running eastbound, they ended up deadheading one trainset back to CHI, or maybe running it in tandem with another (I can't remember that part), just to get the equipment back.
Marias pass closed during the blizzard, and again a couple days later because it warmed up, and all the unconsolidated snow (just like we have now) slid onto the tracks. It is supposed to warm up in Montana about Sunday or Monday...
I expect more closures as the weather warms up, because they will have snow slides. BNSF may have said, we are going to have a mess, we don't want passenger trains to be part of it.
And BTW, this might happen once a year for a week, and many years it never happens at all. I have taken many an EB train in the winter, and freight traffic runs on the hi-line all winter long. To suggest cancelling all the trains all winter is like saying people shouldn't live where it snows. Should they cancel all Amtrak trains in Florida during hurricane season, or all trains across the Midwest during tornado season?