Cut squash in half; discard seeds. Place cut side down in an ungreased 15x10x1-in. baking pan. Add water. Cover and bake at 350° for 40-50 minutes or until tender.
Meanwhile, in a large skillet, cook the sausage, mushrooms, onion, celery and garlic over medium heat until meat is no longer pink; drain. Add wine. Bring to a boil; cook until liquid is reduced by half. Stir in the soup, croutons, milk, Parmesan and 3/4 cup cheddar cheese.
Drain water from squash. Turn squash over; stuff with sausage mixture. Sprinkle with remaining cheddar cheese. Bake, uncovered, for 20-25 minutes or until heated through.
