Pack light, take only what you need. Really. Truly. In fact, you should probably only take half of what you think you’ll need and even that’ll probably be too much.
Spread everyone’s clothes across all your suitcases. If one bag is lost then one person doesn’t lose everything.
It’s easier to manage a number of lighter weight bags than one seriously heavy one.
Give each child their own bag to carry with their special belongings inside. The small kids’ carry-on bag with wheels and the extendable handle is the easiest for kids to manage. They can always pull a bag they can’t carry.
Pack your bags for your trip and then carry them around the block. It will inspire you to rethink what you packed and simplify.