Flaming Gorge to Page Az. Monument Valley, Escalante NP

After Moab have you considered Mesa Verde National Park known for its well preserved Ancestral Puebloan cliff dwellings? Valley of the Gods is an interesting drive through. Bryce and Zion are also near your route.

While we like water related areas we would go to GC N Rim before L Powell which may also have very low water levels, detracting from the scenery for us.