Agree completely with my friend BB_TX, and post only to add that the drive from Pagosa Springs to Chama is one of our favorites, beautiful mountain vistas. The first part of US 64 is also nice, only the last part as you near Taos is rather desert like. But you do cross the Rio Grande high bridge.
We have made every mile of the route you intend--some of it many times and both ways. The most serious part is Wolf Creek Pass. We have never had a problem with the pass, but you need to be in full control on the descent. We tow a fifth-wheel, but I'm sure the same thing would apply to a Class A--keep the speed under control--use brakes only as needed.