Combine 1 1/2 cups vodka, 1 cup lemonade concentrate, and 4 cups ice cubes in blender. Blend to just smooth but still slushy consistency. Pour into large pitcher. Repeat with remaining vodka, lemonade and ice. Add to same pitcher. (Can be made 5 hours ahead. Cover and freeze.).
Whisk lemonade gently (do not blend again). Pour into 8 tall glasses; garnish with mint and serve.