My BIL makes his living as a logger and drives in all kinds of conditions. He has a diesel pusher and does not usually stay in rv parks. He has been caught out in bad areas and had to stay in the rv for days and has eventually had to find a rv park. Now the area you want to drive through is not weather friendly and if going to the canyou would probably find it closed to rv's/large vehicles. The roads you have questioned are ok but not maintained the best particularly on the reservations and are somewhat isolated at times.
As others have said rent a van or a class B unless there are more than 2 or 3 and plan to motel it. We have been caught trying to go north on I 25 and had to stay in a motel due to freezing roadways and steep roads not a nice thing at night as you should be aware. Besides if its only for 5 days you will spend most of it driving anyhow with little time to sight see and if it snows you just might sit in 1 place for the 5 days!! PHX to GC is a full day drive not counting driving thru the canyon area so stay in Flagstaff. Flag to 4 corners is about a good 1/2 day drive although there is really nothing to see at 4corners IMO and then to denver will be at least another 1 1/2 to 2 days particularly if trying to sight see! So at best you would be pushing your luck weather wise and not really enjoying the trip vacation wise.
If ya need get a copy of the latest trailer life, they have article on things around the east LA area, Sedona, and the places around there to visit and as noted you can come down to the tucson area and visit what is around here and down to the border if that excites you.
