Rob, my advice, take things one step at the time. You will know your interview date before May (actually it is probably going to be around two months after your FP date, so it should be some time in April)
Usually, if you pass the interview, they give you the Oath date right there. That should be, based on the experience in this thread, some time in June. If that overlaps with your travel plans then you can decide what to do.
If it were me, I would plan around their dates and not the other way around. They don't like it when people reschedule, so they make it a point to slap you on the wrist when you deviate from the "cookie cutting" proccess. How do they slap you? They will make you wait a while.