You will probably see sub freezing temps, at least overnight, in Bryce Canyon at 8000'. Water will be a problem. Best to tell the rental place where you're headed, and get their take on it. If you damage the RV by negligence, you're probably on the hook for the repair costs.
Mike. Comments are anecdotal or personal opinions, and worth what you paid for them.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 Wrangler JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)