It will still be busy that time of year, as we went almost the same time, but got off a boat in Miami, and arrived the 28th, until the 31st. We find it cheaper to generally go into Orlando, and yeah, we seem to always want some park fun before or after a cruise. Two years ago, we got off the boat by around 8:00am, and were at the Royal Pacific by around 1pm, as we stopped for lunch before checking in. We hit the parks that day, as I got my family, 4 day tickets, and I have an AP. More time for fun, is always what we look forward to. Even trying to get a late flight back, to have some more park time.
I'd do 3 days, even if you only have the afternoon and evening at the parks the Sunday you arrive. I would think your kids would be so happy to drop their bags and have some park fun, particularly after ending their cruise fun, and being in the car for a few hours. Like Disney, there is not much difference between 2 and 3 day tickets. And yes, get the park to park ones. So easy to move between IOA and the Studios. Plus, you can get a lay of the land that first day, and then get a good night's sleep, and take advantage of the early entry the next day. By the afternoon, the crowds will be there, and even with express, you may see longer lines. If I remember, Mummy was about 50 or so, minutes, as was Kong. And I'd buy the wands that first day too. Time to buy, depends on how long the check out line is. And those Potter stores can be packed, as they are small. Sometimes there are lines for the spells, but everyone seems to be polite, and wait for those in front of them, and generally, there is a team member there to help with the spells. The light show is nice, and to beat the crowds, you may want to view from the bridge. I think I'd save it for your second night, as many wait for it, as the show time gets closer. If you can, near the stage is good, but you need to get there early. They start blocking, to make a path for those not wishing to stop, and get out of the Potter area, a bit before it starts. They may show it more than once,a night, so make sure you check the daily list of what's happening that day.
Have fun, it's a great time of year to be in the parks, as they still have the holiday decorations around.
What a great time for your girls, a cruise, then park fun, before going home. Nice surprise gift.
And yep, we have gifted trips to our kids as they became teens. Now that they are college kids, the vacation time has shifted to after the holidays.
