Don't worry about Utah in August. it is not that bad.
Out of Cedar City take Hwy 14 ,12 to Torrey on the east side of town there is a camp ground Thousands Lakes RV park they have all types of camping cabins and laundry. to fit any budget. you may have to stay a day to see all the sights.
Fish lake Hwy 25 goes all the way through paved don't let your gps fool you.
24 through Capital Reef is a nice ride also.
you can go to Colorado from hear or north towards SLC.
If you head north from hear take hwy72 to 70and 10 to Huntington. this is a boring ride but in the middle on the west side of the road is the official UFO landing sight. You will need to stop in talk to the retired guy that built all the stuff. It is the nest off the map tourist sight I have ever seen.
From Huntington take hwy31 to 96 to Scofield res. and Hwy 6. From there you need to go south a few miles to Emma Park cutoff east to 191 north to Duchesne. Then north on hwy35 to Kamas.
from hear there is a few directions that can go. the Mirror Lake hwy150 or make your way to hwy 65 and 66 to Morgan. north on hwy167 then 39 and 16.
From there you will hit 89 right will take you to Wyoming and left will take you to Idaho. Both will get you to the same area.
There is a better description of the middle pare of this ride described in a post on this sight under R&B ride and your envied. you will be doing it in reverse.
If you post when you will be in Utah there are several of us that can hook up and ride with you on several parts for this route.
Send me a PM and Ill give you more information.