Still haven't found a site on it per se, but I did find a few sites mentioning people with blow-up Grinches on their roofs. This family looks like they have fun decorating:
Family has holiday cheer, and so does their house
Schoolchildren aren’t the only passers-by that have stopped to see the Madalones’ 8-foot-high blow-up Grinch and Frosty the Snowman, among the other frills.