The setbacks were evident for travelers around the country. On Christmas Eve morning, mats, blankets and pillows lined the floors of the Twin Cities airport, where people had been forced to sleep the night before.Catherine Lynn, a sales specialist in Watersound, Fla., said she had spent more than two hours on Friday attempting to rebook a flight for her son, who learned his flight that afternoon had been canceled when he tried to check in on the Delta app. Ms. Lynn said she was happy that she had been able to book a new flight for her son for Friday evening, but she will have to drive to a farther-away airport to pick h …
