Need some advice

You could possibly still get your fix of rving. You could rent one in Las Vegas for a week when you are exploring the Grand Canyon area. As long as you don't mind sharing with the other couple, you could rent one rv for the week. The rental car would still be valuable, as travelling to tourist destinations in a rv is not ideal, especially if you have never driven one.{and the steering wheel is on the wrong side}.You could just follow behind with the car, as it isn't too long of a trip. Las Vegas is only four hours to the south rim. It is about a twelve to fourteen hour drive to complete a loop around the Grand Canyon back to Vegas. This could include, Oatman, Kingman, Flagstaff, Williams, South Rim, and Page, all in Arizon. The Utah part of the loop would include Zion National park, and for a few extra hours could include Bryce Canyon. Heading back to Vegas, you could take in the Valley of Fire State Park. As this loop is only about 12 plus hours to drive, depending which places you include, it could easily be done in a week. It could be expanded to include a few other places if you felt like it. This could include Monument Valley, the north rim of the Grand Canyon, Sedona, Beringer Crater, just to name a few off the top of my head. This loop is my favourite area to visit. Being Canadian, I enjoy seeing the wonderful scenery of this area. It is second to none. Oatman, Kingman, Williams, and Flagstaff are part of the old Route 66, if that has any interest to you. There are also still other towns on side highways that were part of it as well. Just a thought. Good luck on your trip.