Unavoidable trans-Pacific flight with 18-mo-old, need advice how to keep sanity

My wife and I are traveling in upcoming months which entails a 15 hour leg on a trans-Pacific flight. Some weeks later, we will be taking the reverse trip back. Our daughter will be 18 months old at that time, and we want to mitigate as much as possible any problems for her and her comfort, for us and our sanity, and for the other passengers. We will be in coach and she does not have a seat of her own.Anyone that has gone through a similar trial: what lessons did you take from the experience, or what advice can you offer?Steps we have already taken:We endeavored to book the flight that was a majority over-night. She sleeps really well at night and usually is out for a good 12 hours.We have already taken a number of shorter trips (2-4 hrs) by air and rail to acclimate her to the experience. To our surprise, she made a quick realization that taking a few sips from her sippy-cup relieves ear pressure during take-off/landing.My wife and I are thin enough that during cruising, our daughter can sit between us comfortably with the armrest raised and a blanket behind for comfort.Over the last few months I've explored her tastes in kids' movies and she has taken a strong favoritism towards Tangled and Frozen. We loaded these onto an older iPhone with a durable case and cover over the 'home' button and she now enjoys watching these movies using the iPhone. We then bought several pairs of extremely cheap over-head headphones (the kind with the thin metal headband and puffy foam earpieces like were the norm 20 years ago) and taped the band to stay her size. They are so cheap of quality that the maximum volume with the iPhone is well within the safe zone for her ears and she is not going to blast her ears messing with the volume buttons. She is now comfortable sitting and watching Tangled/Frozen on the iPhone with the headphones for about 45 minutes with only occasional help readjusting. On our last flight, we were able to hang the phone (using an attached ring-stand) on the seatback tray latch and she quietly watched for upwards of an hour.Plan on getting some earplugs for her and test how well she sleeps with them inserted after she is asleep. After an initial "dead" phase of her sleep cycle, she becomes a little sensitive to sounds much different than the ambient. via /r/Parenting http://ift.tt/2bKfH8N