I agree with what DrewE wrote. And that has been our experience. We used to travel toadless with our 23' Class C. Changed campgrounds pretty much every day. Left one campground in the morning, did our sightseeing, shopping, etc. then found a campground up the road. Sometimes only a few miles up the road! But those were the days when RVing wasn't as popular as today. Now you need reservations at alot of places.
Over the years, we bought bigger and bigger motorhomes. Now we have a toad and stay at campgrounds many days each. So our traveling/camping style has changed.
Sometimes I do long for the olden days when we traveled more simply in the smaller rig, could drive and camp down any forest road, etc.
Sounds like you want to go on this trip without a toad. It is certainly possible. Like DrewE wrote, you just have to plan that way. But there are some sites where parking might be difficult/crowded. You just have to accept that.
I suggest that you take a short camping trip with the family close to home with your new-to-you GMC before you venture across the country....a trip where you go sightseeing each day, to mimic the big road trip.
I would definitely stay at the campground inside the GCNP South Rim....Trailer Village. Make reservations!
