I'm sorry I didn't hear about this trip last fall. I love going to Big Bend. Another alternative for primitive roads is Big Bend Ranch State Park. It's just west of Terlingua, and even larger than the National Park.
Cell phone coverage through out the the are is spotty, but Big Bend Amateur Radio club has a radio repeater system that covers much of the Big Bend country, including the parks. It would require people get a Technician amateur radio license. It takes a 35 question test, mostly about rules and allowed frequencies, and operating procedures. The test costs about $15, and is good for 10 years. New 2 meter radios are available for under $50 for chinese radios to a couple of hundred dollars for name brands.
For those that choose not to camp, there is a nice motel at Chisos Basin, but be sure to make reservations. The restaurant has a great view over the basin. It is a steep climb into the basin with a couple of tight turns at the top of the pass, but commercial buses make the climb without issues.
I haven't bought a MV yet, but I might join you if the time is right.