MIX graham crumbs and margarine; press onto bottom and up side of 9-inch pie plate.

ADD boiling water to jelly powder in large bowl; stir 2 min. until completely dissolved. Add enough ice to cold water to measure 1 cup. Add to jelly; stir until slightly thickened. Remove any unmelted ice. Add 3/4 cup Cool Whip; stir with whisk until well blended. Pour into crust. Refrigerate 4 hours or until firm.

TOP with remaining Cool Whip just before serving.