I dont want to go up and down stairs 5 times so I encourage parents right from the start to help the child learn to crawl up and down. I now have my 2 oldest napping in the playroom but that still leaves 3 so I carry the smallest one for now and the others crawl up. If that doesnt work and you dont mind going up and down, put a gate and the bottom of the stairs so that the ones that are waiting for their turn cant start going up.