In blender, place 1/2 cup of the grape juice, 1 can lemonade and 1 bag strawberries. Cover; blend on high speed until smooth. Pour into 4-quart nonmetal container; repeat. Stir in remaining grape juice.
Cover; freeze at least 4 hours, stirring occasionally. Remove container from freezer 30 minutes before serving. Just before serving, stir in carbonated beverage. Garnish as desired.