Well, in the great peanut butter cup experiment it appeared that the frozen insulin still worked, although its action curve was slowed. So it was suggested that we try again without administering food, to see what action the insulin had.
We waited for a reasonably flat period, we were at 165 for about 45 minutes, and we administered 4 units of previously frozen and thawed Humalog. As you can see in the resulting Dexcom tracing, the insulin still works. It does appear to us to have a slightly elongated action time as compared to unfrozen Humalog, but it still works.
Our son should have needed 36 carbs to offset “fresh” insulin, and that is what it took to come out of the lows.
So, our conclusion is that if you have an emergency, and access to once frozen insulin, go for it, but test often.