I was told that solu-cortef lasted 8 hrs. That would be enough time to transport. We live in a very small town and I gave the EMS a bottle of solu-cortef to keep in the ambulance. I also have a medic alert bracelet on my son, and when someone calls them they are told to look in a black backpack which has another injection.  Hopefully we’ll never need to call EMS  but we’re prepared as much as possible.
Oh yeh our family dr. wrote letters to all the nearby hospital’s emergency rooms and said that if this child ever shows up this is what his endocrinologist recommends. Then he attached a letter from her.  I hope we’re covered.