I did one day at WDW after my five night cruise and while I had a good time, it's not something I'm likely to do again. Part of that was the drive up from Miami (just coming from Port Canaveral would be a lot less to deal with, I think), but in general I found it weirdly stressful compared to previous WDW trips. Having one last day before I had to go back to the real world made me feel like I had to cram everything in and I overtaxed myself (though I suppose I might have done that if I had just one day pre-cruise, too). And then, too, WDW just felt very loud, crowded, and chaotic after the cruise, and there was major sticker shock when it came time to pay for meals. I was dealing with sea legs/dock rock the whole time I was in WDW, and I think I delayed my recovery from it by not getting enough sleep.
Had a great day despite all that, but I'm not doing it again. I think it'd be much better to go a day or two ahead of the cruise and then just head home afterward. To be quite honest, when I got off the ship I was perfectly ready to board a plane and go home and it was only the fact that I'd already paid for everything that got me in the car to head to Orlando--and that's coming from a total WDW nut.