Replying to my post with an update...our streak of 40+ years of flying without ever needing an overnight stay is intact! My wife's first flight was 2.5 hours late, and her connection was only 90 mins. So while in the the air, she got confirmed on a flight for the following day, and was going to handle the hotel and food when she landed. But fatefully, her original second flight was delayed 2 hours. So she ran thru DEN and made her original flight! Once the new flight was confirmed, I thought they would cancel her original ticket, but no. She boarded normally, except for being out of breath. 2 separate MX delays of 2+ hours on UA saved her!