Mostly I disagreed with the comparative ease you implied for mechanical troubles with cars. I've never had or heard of a tow truck getting there that fast outside of things like highway blocking accidents. Holding up the time of repairs and alternative transportation as specific downsides of trains also felt off, as did the remoteness.

https://www.cbsnews.com/detroit/news/amtrak-passengers-stuck-for-hours-on-stranded-train-near-battle-creek/

This is a story more like what I imagine with a train breakdown. The "middle of nowhere" was a half mile from a road, ten from a city and near enough to a city that they got busses in a few hours. It's by no means nice but it's not quite "stuck in a mountain pass for the winter".
In my experience cars often go to places far more inaccessible, so it seems odd to single out trains.

To me the biggest difficulty would be the slowed information flow. When my car breaks down I know exactly how much I can do to repair it before I call or start walking. I have no idea where the mechanical assessment of the train is so I don't know when to bail.

Edit:

Oh, right: they put fences around the train tracks? They don't do that here that I've seen outside of junctions. Much bigger fences around the highways.