I am a Scout Leader.......... and that advice is so 40 years ago. 1974 has come and gone and kids today do NOT care about that. Try that and I guarantee they will absolutely not want to come on the next trip.
Ask them what they want then come to a compromise. I've been a Troop Leader for 10 years, ask them what they want. Kids want to have input, they want to be involved, they want to be part of the process.
Agreed. A Scout Manual, planning and preparing a meal, a hike where you describe plants and trees, those ideas worked when my boys were about 5-9 years old. Not for today's teenagers. Our last big family trips, I gave everyone a list of things to do in the area, and had them choose six. We did some things together, and split up for others. It worked really well.
I am not comfortable leaving two teens home alone. Three of youngest son's classmates, home alone, had a party show up at their house after word got around that parents were gone. One friend opened the door for three or four more people, who let in about forty more with booze or worse. Police were called, kids fined, vacations and carpets ruined.
The midpoint of your trip is near ND oil country, so reservations are a good idea. I've enjoyed Fort Abraham Lincoln State Park in Mandan, ND, on he bluffs above the Missouri R. It's about 10 miles off the interstate, so the Bismarck KOA may be more convenient. Makoshika State Park in Glendive, MT, is also pretty, though it's a haul from St. Paul. Medora, ND, is close to a midpoint for you. My preference there is Teddy Roosevelt National Park CG nearest to town or the municipal park CG. Buffalo roam freely in the NP, including in the CG, heads up.
We didn't grow up camping, as our parents were too busy working. Family vacations were visiting relatives over holidays, or day trips with neighbors. When we married and had kids, we were determined not to miss the things in our kids' lives that our parents did. The kids got into scouting, so we attended a few camps with them. Tent camping is not for us. As the kids got older they were busy all summer attending/competing in events. So, we bought an RV and can park, eat, sleep a few hundred yards away. We are soon to be empty nesters, and we're really excited to be fledgling snowbirds.
DS has a moose guard on his pickup. He's hit 7 deer in the last four years without as much as a cracked headlight, and we grow big deer around here. BIL was driving semi at night and hit part of a group of horses that were on the road. The moose guard took a beating on one side, and one side of the truck and trailer needed repairs. It was mostly cosmetic. Structurally the truck was OK.
We don't have bunks or a dinette. Our kids are too tall for them to sleep on, anyway. The one who RVs with us most often claimed the sleeper sofa. Anyone else gets a backpackers mattress and a sleeping bag. Sleeping bags make it easy to make up the bed. Our friends had a rig with bunks until their kids got to be 12 and 9. The 12 year old couldn't stretch out any more, and they both found it too stuffy with the blackout curtain closed.
DS likes to have glazed salmon and corn on the cob from the grill.
Tuna macaroni salad made with green olives, or ham & cauliflower pasta salad, is an easy meal with fresh fruit or a nice tomato.
Grilled peppers and onions are handy for topping burgers and sandwiches.
We like a frittata for a quick hot meal.
Haven't read all 7 pages of replies, sorry. For your carsick youngster, here are a few suggestions from a champion cookie-tosser.
First, have him sit toward the back of the group, so he's always facing forward. Turning one's head to talk, especially facing the rear of the vehicle, can make some people sick in a blink. Second, stay seated while the coach is moving. If he's moving one speed/direction and the RV is moving another, he might get ill quickly. If he must get up to use bathroom or whatever, make sure he is always facing the windshield. Third, games, reading, even watching movies may not go well in an RV that bumps and sways. Last, ask at the pharmacy counter for children's Dramamine, just in case. I also find that an instant cold pack (for sprains) applied to the throat calms nausea. The front passenger seat is best, if you can make that work.
Our dear friends are going next week. They were looking forward to a relaxing trip, no real plans, figure it out when they get there. DH and I explained that it's really not that kind of vacation. It does pay to read up on it a bit so you know what the big attractions are, how to get/use fastpass, and book some restaurant reservations. If you don't like waiting in long lines, then don't -- go enjoy something else with a shorter posted wait time. There is a lot more to do than just rides. There are live theater shows, fireworks, parades, stunt shows, cultural experiences, character meet and greets, playgrounds, face painting, animal encounters, live music and more.
The DS likes the one on the couch, saying it's way more comfortable than a regular sofa hide-a-bed. But he doesn't travel with us all that often, so the daily setup/takedown isn't an issue. It takes an extra three minutes compared to a regular sofa bed.
We have a sleep number air mattress on our main coach bed, too. I am not a fan of air beds or waterbeds. To me they aren't comfortable, and I wake up aching. However, a 2" memory foam on top is a game changer, making it just right for Goldilocks.
Is there a good kennel in your area or at your destination? That might be a happier experience for pooches than a hotel room. My relative has run one for years. Pups get lots of attention and time in the off leash dog yard. They are returned to owners freshly bathed and groomed. Last time we stayed in a pet friendly hotel, our neighbors left their Yorkie alone in the room, and it barked for the entire five hours they went out to dinner and a show. Poor dog, and a lousy evening for us. If you take them to a motel, how will you go out to eat, shop or sightsee? You can't take them into a cafe with you, and they aren't to be left unattended in the room.
When my boys were that age playgrounds and sidewalk chalk didn't interest them. At that age they were allowed to wander in the CG as long as they stayed next to each other. No swimming without mom or dad. A good ball seemed to attract other kids for kickball or four square. Capture the flag is always fun, especially if you invite a few neighbor kids and parents to play. I taught them how to use a compass and would hide something for them to find. Geocaches can occupy time, too.
By age 12 my kids were more interested in spending time with other kids.