Originally Posted by
BBSHOPSINGER
It really depends on your tolerance for the change fees and how important it is for you to get to Japan at the time you have scheduled. If your connection is missed, they will rebook you on another flight as soon as possible. So if you want to save your money and don't mind so much if you're late, just keep your flight as is.
Not true at all. Depends on your meaning of the word "possible".
The OP has no status, and thus is very low on the list in case anything happens. What if another flight gets cancelled as well? Or they are full?
That said, if you miss the morning flight it appears no more flights til the next day (UA or NH)-not sure how good UA is about putting you on other carriers, because then there would be more options, but I wouldn't count on it.