Re: frozen breastmilk and airport security
I bought a cooler and packed frozen BM in bags inside it that I carried on the plane. In the cooler I packed those frozen blue ice packs and regular ice in bags. I tossed the regular ice bags right before I went through security. Then when I was through the security I stopped at one of those fast food places and filled my cooler back up with regular ice.
The milk was still frozen solid during the trip and made it to the hotel just fine.