If the kids start to get on your nerves, that’ll shut em up for hoursssss. 😛
Ya 6 month old is not likely to settle down with a video game, let a lone benefit from it.
snacks are a big distraction, as are new (to them) toys and books. Get your 3 year old to help you make up a small ‘travel kit’ where he/she can choose treats and toys to put in it but only for use on the trip. It will get them excited and thinking about how to amuse themselves.
I dont have experience taking a double stroller on a trip, but call your airline. They probably can help. Also ask for their recommendations and perhaps they can provide you with some additional assistance when boarding? It cant hurt to ask!
I like the idea of having them in their jammies for the trip… it might work.
Good luck!