Stir boiling water into dry gelatin mix in large bowl at least 2 min. until completely dissolved. Add enough ice to cold water to measure 1 cup. Add gelatin; stir until ice is completely melted. Stir in lime peel and juice.
Add whipped topping; stir with wire whisk until well blended. Refrigerate 15-20 min. or until mixture is very thick and will mound. Spoon into crust.
Refrigerate at least 4 hours or overnight. Store leftover pie in refrigerator.