Prepare 1 envelope Dream Whip whipped topping mix as directed on package; set aside. Sprinkle 1/2 cup diced strawberries with 1 teaspoon sugar; set aside. Prepare 1 package (10 1/2 ounce) Jello brand cheesecake as directed on package, blending 1 cup of the prepared whipped topping and the strawberries into the filling after beating. Pour into crust. Chill at least 1 hour. Just before serving, garnish with remaining whipped topping and additional strawberries.