Wow Michel, that is indeed a scary incident. Some random thoughts about things you can do.
1 - buy a metal bowl, put some change in it, put the phone or dexcom reciever in the bowl at night, I promise you it will wake the dead. We don’t use it all the time, but when my wife and I need some sleep, we use this contraption to ensure our son wakes up and treats himself.
2 - aim for a higher target at sleepaway camp. When our son went to diabetes camp, they fed them carbs 6 times per day, and only dosed for those carbs 3 times per day. While this isn’t good for longterm care, it certainly ensures no one goes low. On the flip side, it was really hard to gain control back after this treatment scheme. So there is that as well.
It is a little troubling that the camp director wasn’t on the phone with you or your wife as he was working through the situation, I would definately try to correct that in the future. Scary stuff indeed. Sorry for the random nature of my post.