I was a bit
at he title, but you're aksing for suggestions for a longhaul flight. totally reasonable. floggingmolly, that was really harsh and judgy. OP is going on a longhaul flight with 2 little children, and will have the ipad with her anyway, why not ask for suggestions for it?
OP, as well as a few cartoons, peppa pig, octonaughts etc, i would put maybe some basic games on, like animal flashcards, my first words, my toy box etc.
And get a headphone splitter! Aside from the ipad, lots of little things, like the macdonalds toys, and sweet/snakck, drawing, books etc etc etc.
I have flown many a time alone with my 4 dc, but never long haul, so I don't envy you, and wish you luck!