For croutons, preheat oven to 375°. In a large bowl, mix melted butter, garlic powder and pepper. Add bread cubes; toss to coat. Transfer croutons to a 15x10x1-in. baking pan; bake, stirring every 5 minutes, until golden brown, 15-20 minutes. Cool in pan on a wire rack., Meanwhile, in a 4- or 5-qt. slow cooker, combine the first 5 soup ingredients; pour in broth. Cook, covered, on low about 2 hours or until vegetables are tender., Increase slow-cooker heat setting to high. Mix flour and water until smooth; whisk flour mixture into broth. Cook until thickened, 30-40 minutes. Stir in wine. Whisk in cheeses until melted. Add chicken and ham; heat through. Serve with croutons., Freeze option: Before adding croutons, freeze cooled soup in freezer containers. Freeze croutons separately. To use, partially thaw soup in refrigerator overnight. Heat soup through in a saucepan, stirring occasionally; add broth or water if necessary. While soup is heating, thaw croutons at room temperature; sprinkle over soup.