This is similar to something I noticed and asked about three years ago.
This morning there were two entire CZ looking train sets sitting in Denver Union Station. This was 7:30-8:00 a normal time for the westbound CZ to be in the station. However when I left this afternoon one of the sets remained and it had five locos on the point. 3 of the normal Amtrak and two Union Pacific SD70s. Does anyone know why? Is this somehow related to the frigid weather.