Free-spirited daughter and her plans to live in a cabover

The trial driveway camping idea will give her a realistic preview of things to come. Also, instead of "telling" her things, use the Socratic method i.e. ask her questions instead of offering advice or opinions. For example, what will you do if you discover you are too cold to sleep through a frigid night? or ... What will you do if your solar panels can't keep up with charging the battery when it is cloudy? You get the idea.