As soon as Mom left, it seemed, Grandpa arrived to chill with his great-grandkids for the weekend. Grandpa has 33 great-grandkids; he says so at least once every two hours in case you forget.
Since Grandma died a couple of years ago, Grandpa spends most of his time touring around to see his family. It's kind of like how the Grateful Dead toured, except Grandpa doesn't play an instrument or use illicit drugs and you don't have to call yourself a "Grandpahead" if he comes to see you and you can remember the show when he's gone.