Place the turkey carcass in a large, deep pot and add the stuffing, celery, carrots, onion, bay leaves, poultry seasoning, sage, and chicken broth. Pour in additional water if needed to cover. Bring to a boil over medium-high heat; reduce heat to medium, and simmer for about 1 hour, skimming off any foam. Remove the carcass and any bones. Pick any meat off and return to the pot, discarding bones and skin.