@eli Thanks for the link. We have travelled a lot too (nothing this long). We do the iPad with no sound thing as well. On our last trip, he played with the boarding passes for about 2 hours. That was a pleasant surprise.
We went to Maui on our honeymoon, then a second trip split between Maui and Oahu. Going to the big island this time. I went to Kauai as a kid with my parents.