Something else just occured to me. You are in Houston and Mount Zion NP is @ 1,400 miles away. You will find driving a RV to be slightly different than your car
You will find that gas milage decreases dramatically at speeds above 60MPH, and your RV is not going to get Prius-class milage anyway
so, refuling stops will be more frequent (I will let other Solera owners chime in with their range) but for us, 300 miles = 1 tank of gas when I am driving flat and on 60MPH cruise control. You, however, will be pretty much driving uphill all the way to Utah
so plan refueling accordingly.
Most RV'ers view anything over 400 or so miles a day pretty taxing - especially with your toad. So you are looking at 6 days of your 2 weeks just driving (3 up, 3 down). Just say'n.
The good news is you should be able to plan your trip and drive each day to a campground that has full hookups (and perhaps a swimming pool!)
Once you get to Zion, there are several RV Camps outside the Park. Inside the park, Watchman Campground (In Zion Canyon) has Electricity only and a central dump station.
And, if I were you I would pick the camps you want to stay at and reserve now!