The Million Dollar Highway was a feature one week on America's Deadliest Roads (or was it Worlds Deadliest Roads) Anyway it was a feature. I drove it once going South in a 36ft gas MH with towed. Beautiful but for me it was hell on wheels. Steep tight turns, shear drops, no rails, OMG. I've driven it a few times since in the car, leaving the rig in the campground at Durango, a really lovely drive through beautiful country. That said, you obvious have much more experience than I, Trucks do make that route regularly (another reason for the white knuckles as you can meet a big rig at a steep tight turn). If and when I travel that way again I would go around on the 25 and across. The last few trips to that area took us from Flagstaff up to Durango, then we use the car to travel to Orway and Silverton.
Happy Trails.