You have 30 days to "capture" photos once you download the first photo. So the photos are good through 45 days after they are taken. So theoretically those combined are the maxim days you can capture new photos. You download the first day photos on day 45 and then capture for another 30 days after that first download.
Some folks have figured out that very close trips can stretch one memory maker.
In your case I'm guessing your onsite and offsite stays aren't running 75 days so you wont have any trouble at all!
Have a great trip. Also watch for special spots to capture 'animated' shots and magical shots! They are so much fun