You can just go stanby for an earlier LGA to IAD flight. I did that recently out of DTW to EWR. I had a tight 2 hr. EWR connection to international so the day of departure I had United put me on the stanby list for an earlier DTW to EWR flight and I got on. I was glad I did as my original 2 hr. connection flight was delayed.

It was really annoying to be put on the stanby list at United though. I could not do it using their app or Kiosk as they advertise. I asked at checkin and the agent at DTW said she couldn't do that and just seemed lazy so then I had to call. She had time to just stand there while no one else was even at the desk that time of day to checkin.

It took the agent on the phone 45 minutes to not be able to help because she said the flight was full and thought it was a partner flight which was totally wrong. It was on United. I advocated to have her still put me on this stanby list even if it was "full" as things change and open up. She just had no idea how to so made up excuses. The agents are not the most helpful at United. Then I had to go ask again at the DTW checkin desk and some guy finally helped to get me on the list, where the other agent refused to help. It took him two minutes to do this simple task. I got on the earlier flight.

I would either change at 24 hours or request to get on the stanby list for an earlier flight to IAD. One hour connections can be a huge issue at United. I try to book 4 hour plus connections for international now on United with all their problems, poor customer service and bad IRROPS response.

When I can't book these types of connections I try to move up on flights with stanby or use the 24 hr. change.