I actually like a Great American Road Trip idea. But instead of touring every damn horse ranch in Wyoming, change up the scenery and try to hot every US region. Families have the same car, money provided, production provides gas. Really mix it up, have one leg do a lot of heavy duty driving, visit National parks or wonders (ex. Crater Lake Oregon), outdoorsy detours and roadblocks. Then follow with a leg that most takes place in a Metropolitan area whether it's using local transportation or driving themselves. Imagine a leg dedicated to driving with only a map in somewhere like Seattle (oh you think this street goes through WRONG!) or Boston. The drama writes itself. That way it's a good blend of rural an urban.
Don't make it families only. Have groups of friends, coworkers, bride with bridal party, old lady bingo club, I don't know get some interesting team dynamics.