Pour water into a 9-cup ring mold to a depth of 1/4-inch; freeze until firm. Arrange strawberries and mint leaves on top of frozen layer. Pour 3/4 cup ice cold water over top, and freeze. Continue adding 3/4 cup ice cold water and freezing after each addition until mold is filled. Freeze overnight until solid.
Combine syrup and brandy in a large punch bowl, stirring until well blended. Stir in Sauterne. Just before serving, stir in club soda and champagne. Remove ice ring from mold, and add to punch bowl.