Crossing TX on 2ndary roads

In my experience Texas side roads are as good or are in better shape than most states main highways. If you do not mind adding about 60 miles to your trip a great park to spend a day or so is Kerrville-Schreiner Park. We stayed in the deer field loop and had deer wandering through our site. You could take 41/377 from Kerrville to Del Rio and pick up 90 in Del Rio.
IMHO with as close to the border as 90 is I would only stay in RV parks and would not boon dock.
Do not know where in AZ you are heading but here is some ideas.
Take 136/9 west from El Paso and spend a day or two at Rusty's RV Ranch near Rodeo NM. Incredible night sky's since it is dark sky county and explore the Chiricahua Mountains.
From Rusty's take 80 down around and backup to Tombstone.

Padlin wrote:
Was thinking of being south of 10 by then but I'll mark it down as a possible for the return trip, looks like a nice spot on google map, thanks.

I don't think we've ever ventured south of I-10 except for the time we went to Big Bend NP when we followed US90 west. That road was interesting especially the section west of Del Rio. There is another town along there that also lays claim to the Judge Roy Bean, Langtry.

Was thinking of being south of 10 by then but I'll mark it down as a possible for the return trip, looks like a nice spot on google map, thanks.

I think I-10 is boring until you get passed San Antonio where you at least have hills to look at. If you drive thru Mason TX they have a great city CG. We were doing the secondary road route going from I-20 down to I-10 when we came across it.