We are renting an RV in Phoenix for 9 days at the end of August. Our current itinerary is as follows: Sedona (1 night) Grand Canyon-South Rim (2 nights) Bryce Canyon (2 nights) Zion (2 nights) ...
I'd skip Sedona(Very busy tourist trap) Phoenix & Las Vegas. Instead See Flagstaff area(Walnut canyon, Oak Creek canyon, SunSet Crater loop & Wupatki Indian ruins, Lowel Observatory instead. 4 Days Min.