I am no expert on this stuff, but I would say that we were on easy roads, just not roads you could take a car with a good driver on, by the time my boy was 3-4 months old, but we did not wait more than about 6 months until we started going whereever we wanted to go. Now mine also loves it. He is always asking if we can "go in daddie's jeep." He loves the thing.
Sadly, not into camping. We tried to take him camping a while back and he wigged out, a lot, ended up having to keep him in the jeep for a few hours and he did not fall asleep until after midnight, after I had packed up the entire camp in the dark, and went on the hardest trail I have ever had to travel in the dark. Through the river and two switch backs and he was gone. Figures... oh well, still fun. We hope to get him camping this summer.
I loved the video, that seems like a really great idea! Lots of fun if the kid is going to nap on the way there!