Measure out and set aside 10 ounces wine. Divide remaining wine between 2 ice cube trays and freeze until firm, about 2 hours. 

Add the 10 ounces of wine you set aside, simple syrup, strawberries,, and frozen wine cubes to blender  and blend until smooth, about 1 minute. Scrape blender jar sides down Strawberry Frosé as needed. Pour into chilled wine glasses. Garnish with strawberry slices and serve.