We LOVE southern Utah. We'll be in Zion the last weekend in Oct. :) Some of my recommednations: Not sure how much hiking u do but...Kodachome Basin ST. Park. Great place to camp as well as good hiking & an easy and beautiful slot canyon not far from there is Willis Creek). Grand Escalante Staircase great slot canyons a well...if u guys r in decent shape, Peekaboo & spooky slots r awesome....but VERY narrow, I had to turn sideways in some spots & I'm 6' 170)Devils garden is also down the same road (hole in the rock),. Hike to lower calf creek falls is fairly easy & flat but sandy...worth the effort. Do at least 1 hike down into Bryce canyon. Burr trail is an interesting drive. Be sure to do the cave tour in Great Basin. Check out both sides of Zion NP as one is very different from the other...(I wouldn't hike the narrows in Oct., water too cold for me).
You'll have a great trip...oh, if u don't already have them, I suggest reservations for Zion NP. Oh, if the N. rim is closed....assuming there isn't alot of snow, you can still see the north rim by goin into the Kiaba N. F. ie Crazy Jug Point (we camped here in our 5th wheel all by our selves for a few days a couple of years ago....was great but a chore getting the camper back there....not an issue for a car or truck tho.