Thanks, all! I appreciate the advice.
The allergist’s office is going to get him an Auvi-Q so he has something a bit smaller and give him a letter for the plane.
I had a good, long talk with ds yesterday about the risks. It has been so long since he had a reaction, that he doesn’t remember them. So I just retold stories of previous reactions he’s had and shared 2 stories I’d read about teenagers who ate something they had reason to think was safe, had a deadly reaction, and died because the epipen was not available. (One girl was driven home to get the epi, but ran out of time.)
I gave him some of the ideas you shared and asked him to come up with a plan for always having it with him. He seemed to take me seriously, so hopefully we can use these next few months as a training ground.