Sounds like a fantastically productive way to spend time whilst on the road. I love the idea of "unschooling" as you phrased it, because schools and their curriculum's are so antiquated. They also don't focus on the areas of life that are important and relevant in the 21st century.

As for the books... I think audio books are super, but nothing beats holding paper in hand. I am one of those crazies that likes to smell books haha!