Flight delays and cancellations can happen anytime, anywhere. We live in Colorado and visit family in FL every December, so we have no choice but to fly out of Denver every winter. Only once were we significantly delayed (a full 24 hours) - and that was because of a mechanical issue, unrelated to weather. We've had a few shorter weather delays - a couple hours or so.
But the chances of not being able to make your cruise if you fly in the day before are still slim. If by some freak chance, it does happen- that's what
trip insurance is for. I know it would be a drag to have to reschedule at the last minute, but it's so unlikely that it isn't worth worrying about ahead of time. And not the end of the world if it does