We have a few green ones, we will still think of something fun to do with them. Back when we were homeschooling and had a Homeschoolers Harvest party I made a mock apple pie. I found the recipe in my Little House on the Prairie Cook Book. No one knew I used a green pumpkin. Love that cookbook-loved feeling like Caroline Ingalls if only for a day.
The best part of harvesting for Mom would be driving Dad's lawn mower.