I don't know the current answer to your question regarding the C&TS, but years ago in the 90's Earl Knoob's late wife Carmen was a EMT and she usually rode along in the vehicle to Cumbres and got on there on eastbound Charter trains. Otherwise you are probably left to whatever EMT runs that area. Years ago with CBS did a spot on the Rotary run (1991), they flew a chopper in and landed at Cumbres. It supposedly came from Farmington, the nearest point to Cumbres for a helicopter at the time. Someone told me they had enough fuel to spend about 10-15 minutes shooting over the Rotary, before having to return to base. So they basically shot Cumbres through Tanglefoot curve and that was it. Down near the highway below Tanglefoot you can hear it in my video (Steam Rotary). A week or two later CBS did a nice little story on it, on their usual end of the week(Friday), feel good story!
One good thing in all this, they do run speeder cars for fire patrol, so if they needed to go ahead or behind to the nearest off loading spot they could have that option. Its an interesting topic and would be interested to hear how the NG guys handle it out there.
Greg