What form does the mind control take? Depending on that, simply physically removing them may not save them.

How big is this palace? Dimensions and/or weight would be nice. Is it small enough to be able to be animated by an animated object spell?

Could a Roc or a flock of Rocs carry it off?

Mirage arcana could create the illusion that it's gone. Combine with a suitable illusory monster (perhaps provided by major image) swooping in to lift it off, and a careful use of magnificent mansion to spirit away the kids by sending them through the door to a "new annex" of the palace. Mirage arcana lasts for as long as you concentrate plus an additional hour per level; honestly, the hour/level is most of the duration, unless you're willing to do nothing for a day or two. Get some compatriots to set up demolition gear to blow the real pagoda's top to rubble so the ruse is harder to discover when your illusion wears off.