I agree about the schools! I always get a tad jealous reading some fo the posts here where the school actually encourage families to take off during the school year. Our teachers aren't allowed to give work in advance and they don't have to allow the kids to make up any work and can give them a zero. (Fortunately, so far all the teachers we've had have been great about helping us out. It's more the district administration that's the problem.
We usually fly in the night before and stay at one of the hotels in the area. We rent from Budget one-way and drop it off at the Cocoa Bch location, then they bring us to the port. On the way home, we do the opposite. Sounds like you are driving down so I guess that doesn't help LOL I've heard some of the hotels let you park at their lot....that sounds like a great option...much cheaper than parking at the port. Plus, it's always good to have that first night in the area. It puts us more in vacation mode, much more relaxing than scurrying around the morning of the cruise. We don't have to worry about delayed flights, lost luggage etc, and we can get to the port as early as possible.
Our kids usually run right for the pool arrival day. They practically get it to themselves! We get lunch, bring it out to the pool area and then they can go swim/slide. On sea-days, the pool areas can get crazy so they stay in the clubs most of the time.