You usually have access to power in long flights between continents and national train lines. But you don't want to play that long on a portable device anyway,

You usually have access to power in long flights between continents and national train lines. But you don't want to play that long on a portable device anyway, position is just terrible for your posture/neck and I don't think it is really healthy. What you want is alterning occupations: video games, reading, sleeping, drawing, card games, listening to music, making music, chatting, eating, moving in the main aisle, etc.