During school holidays routine seems to go out the window. My youngest suffered the most, since she still needs an afternoon nap. I had to find a compromise, allowing her to sleep without the boys tearing the house down from boredom.
I let the boys play Wii, for as long as she sleeps. They make a lot of noise and wake her, game time is obviously over. The motivation seems to work! (It can be fun watching their expressions while they play!)