Place 8 ice-cream sandwiches in a 13- x 9-inch baking dish. Spread caramel sauce evenly over sandwiches. Sprinkle evenly with 1 cup pecans. Top with remaining ice-cream sandwiches. Spread whipped topping evenly over sandwiches. Sprinkle with remaining 1/4 cup pecans. Cover and freeze at least 1 hour. Let stand 5 minutes before serving; cut into squares. Drizzle with warm hot fudge sauce.