I have a plan that sounds good to me, but want to put it out there for the experts to error check for me... My family of four are returning from DUB to BOS around Christmas, but our ultimate destination is Chicago. I need to book our flights from BOS-MDW. We get to BOS around 17:30, and would like to just get home that night rather than spending a night and flying the next leg the next day. I'm looking at booking a flight on Southwest (WN) at 19:05. That's a 90 minute connection. I'm using points, and have enough to book that flight and one the next day. I was thinking I would do that so that if the original DUB-BOS flight is late, I can cancel the flight for the same day and just use the one for the next day. Likewise, if all goes well, I cancel the flight for the next day and get my points back. So, the questions are: 1) Is it reasonable to expect that 3 americans and a green card holder can get through immigration in Boston and onto our domestic flight with 90 minutes to connect? 2) If yes, then is it reasonable to book a second flight just in case something happens and we can't make the one the first day? 3) Anything else I should be considering? Thanks!