A better thing would be for the airlines to keep the money and then fly his daughter and her family to see him at no additional cost to the family. Non refundable is non refundable, but to get to see his daughter and her family would be priceless.
Don't send the girls out in January. When does everyone start a diet? JANUARY. Have them come in May or October. This poor Dad was out with his girls and couldn't even get up to the door before being turned away.