If you consider the solar system at 10^15 meters, it resembles an atomic structure, and explains the reason why quantum gravity is considered feeble.
As Dave suggested, the laws remain regardless of scale - with gravitational-field strength decreasing as distance between objects/particles increases. I would imagine the relative distances would be comparatively identical.
http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10