Current routing for first leg is:
Page, AZ to Kanab, UT, then to Fredonia, AZ, through Colorado City to Hurricane, UT and the to Zion River Campground in Virgin for 4 nights.
Second leg:
From Virgin, up I-15, exit on Ut-20, then down 89 to Cannonville/Bryce Valley KOA for 3 nights.
Not my first/second/third choices for camping locations, but you take what you can get when you dawdle too much before looking for open spots to reserve.
Sounds like I should not plan on towing through Zion, and just enjoy it as a drive when off hitch!
Thanks all for the advice!