Blend together 2 cups cantaloupe, 2 cups honeydew melon, 2 cups orange juice, 1/3 cup lime juice, and 3 tablespoons honey. Mix in 1 1/2 cups minced cantaloupe and 1 1/2 cups minced honeydew melon. Stir in 2 cups champagne, if desired, and serve cold, garnished with whipped cream and mint leaves.