How much longer will we get to enjoy camping with our son?

Somewhere around the teenage years. If they get a job, that often conflicts.

Make sure it stay's fun. That may mean bringing a friend or two along and making sure the destinations and activities are of interest to a teenager.

Another consideration are you the type of parent to keep the kid in 6 organized activities at any one time? Being involved in organized activities is good in moderation but I see lots of families overdue it until it becomes their entire life and everything else gets set aside.