Howdy,
I just did a very similar trip in early September, but the opposite direction. We landed in Phoenix, AZ and drove the first day to Sedona and stayed the night. We didn't spend much time in Sedona.
After Sedona, we made our way to Page, AZ where we stayed for 1 day and 1 night. We went kayaking in Lake Powell which was a great time.
After Page, we went to Bryce Canyon National Park in Utah and stayed there for 1 day and 1 night. We did some hiking in the park which lasted about half the day.
The next day, we got up early and headed to Zion National Park. We hiked Angels Landing the first day, but the end of the hike with the chains was blocked off due to COVID. Some people decided to continue with the rest of the hike anyway.
The next day we did the Watchman Trail early in the morning and then did a small portion of The Narrows hike. We weren't well prepared for the Narrows hike as the water quickly got above waist level, so we turned around as we had to drive a few hours to Vegas later in the day and didn't want to do so wet.
Worth noting for Zion: I believe we had to book busses to get to the trails on both days in advance for $1 each.
After the Narrows hike, we drove to Vegas and spent the night there before flying back to Houston the next day.
Hope this helps. Overall, it was a great trip that my group really enjoyed. Not much downtime to relax, but relaxing isn't really our thing.