we've flown 10 hour flights a couple of times with 1 to 3 toddlers as our family grew.
i'd pick a day flight over a night flight.
have a small pack of sweets for take off and landing to ease ear pressure.
forget about catching any movie (if your SO is with you,
he maybe able to catch movies and eat peanuts but as for yourself, be happy if you get a potty break

).
the children will be entertained with all the meals, mine were thrilled with all the cutlery etc etc and all this eating takes up a large portion of time.
puzzle books, magna doodle, small books were lifesavers.
i'd bring a bottle of water (non spill container for the little one) for each child since they always wanted a drink when it wasn't time for a meal/drink break.
ignore anyone who gives you "looks" if the children act up.
for stopovers, i'd get off the plane and have the kids run around a bit rather than stay in the plane. take your valuables but leave the carryons.
oh and a change of clothing for yourself and maybe two gender neutral sets in case someone throws up on you
i wanted to add that its a great thrill for the children to go for a plane ride so keep positive. i'd prepare them that they will be in a confined space for fairly long time, but they will have fun food, a movie to watch and some new toys to play with.
have a wonderful trip.
post pics when you come back!