If you have any flexibility (+/- a day) in your travel plans, I would think you could work around any irrops of whatever that might result in loss of your GF or BF seats. Especially at the end of your vacation; it's not fun stressing out over having to get back by a given date if something goes awry.

So... make sure you've got a bit of padding and relax. Don't stress over what might happen, especially since, if it does, you can deal with it like a pro. ^