When I bought a queen in June, the man who sold it to me made sure to show me how to keep them in good condition for the next day. He dipped his finger in water and stroked it on the wire of the cage, filling 2 or 3 of the mesh holes. I asked, "And how often should I do that?" He said, "That should last them for 2 days."
One of the metabolic by-products of eating the honey is Water vapor. Though they wont be able to fly, the water their bodies make from the sugars, condensation, and relative humidity should keep them in good shape. Remember they've been kicking around a lot longer than we have, and nobody's "kept" them. Even after we were kicking around Humans spent a lot of time robbing wild hives rather than managing them.