That does sound really scary—glad everything worked out ok!!
I went to overnight camp for many years as a T1 teenager without a Dex and survived, and in thinking about it, I think this is key: My A1c’s and control was never as tight as your son’s (I honestly don’t remember what my A1c was, but I’m guessing our target was more like 7), which probably had its drawbacks, but it really wasn’t possible with the tech (or lack thereof) back then. By running higher on the whole though, I suspect most of us who were diabetic back then had both stronger hypo symptoms at higher levels and were less likely to run low. While I wouldn’t recommend changing your strategy in general, since tight control is great, no reason not to temporarily aim for a significantly higher overnight target (say 150 overnight for a few weeks even won’t likely cause major longterm damage from the highs and may prevent something scary from happening).
Maybe the issue is less about being UNLIMITED and more about striking a balance between tight control and living your life? Sort of like how as an adult, I try to stick to low(er) carb at home, but when I’m on vacation I say f*** it and eat more of what I want and do my best with it, knowing it’s temporary, and that I need a break sometimes.