A line crossing the Rockys can hardly be considered remote, (at least in an integrated system) it should get tons and tons of through-traffic. It's not about where the line is but what it connects.

A line can be way less remote, say just ten kilometres from a million inhabitant metropolis, but still see very limited traffic as the area is rural, and only have hourly passenger service and nothing else, maybe a couple of grain wagons in harvesting season and electrifying it would not amortise in a century or ever (because increased maintenance costs). Completely different situation to having through-traffic 24/7 bumper to bumper somewhere at the arse of the world.