Last trip, 3 weeks, I came back with 10.800 pics on the DSLR, plus a rough 500 on my wife's point and shoot. If you multiply those figures by an average JPG size shot by your camera, you'll get a rough estimate of how much storage space you might need
I must admit that I was less snap-happy than on previous trips, but I also often shoot at 3 or 4 fps, so that's more pictures than one would normally take.
what will make a difference is wether you use your camera for movies (if it's able to do it). Video will be way more data hungry.
A word of advice : if you have a means of backup, don't hesitate (I use a portable hard-drive connected to my android tablet)
Storing everything on a single SD card, and relying on it to live through a Florida trip is a leap of faith.
ETA : just checked the properties of my october 2013 trip folder, and all accounted for (vids + pics) it's 60.5Gb