You would think that WDW's Grand Floridian would be able to afford to install EV friendly infrastructure when charging $500+/night for their 800+ rooms.
Regarding your Raleigh-Disney trip:
Florence looks like a good midway stop between Raleigh & Savannah. Plugshare shows three chargers near the I-95/I-20 interchange (hotel, Nissan dealership, parking lot?). Raleigh to Florence is approx 150 miles. The trip from Florence to Savannah is approx 170 miles. You'd probably need to add 80-90 miles while in Florence to make it to Savannah. As far as Savannah goes (per forum post by others), there are Eaton Level II chargers with spaces reserved for EVs in the Ellis Square underground parking garage. I've personally stayed in the Ellis Square area and found it to be well located. I recommend the Avia Hotel. Savannah to St. Augustine is approx 186 miles. Plugshare shows a Nissan Dealership being the only 'quick' charging available in the area.
Once you leave St. Augustine loaded up, it's just a matter of finding a place at WDW.
TMC user Robballan provided this info regarding Grand Floridian:
"OK, I've drove from WPB to Disney's Grand Floridian in March with my 5-month-old Model S. Roughly 180m each way. I called ahead a week or two in advance. No one at reservations knew anything. So I asked for, and spoke to, the head facilities manager. He was quite excited to hear I was coming, and advised me to ask for the on-duty facilities manager when I arrived. It took a little waiting, but within 1/2 hour of my arriving I was escorted to the employee parking lot, to the golf cart/tram recharging area, and provided a spot with a 110v outlet. He even coned off the neighboring spots for 2 days while I was there. Of course, 110v is less than ideal, but it is what they have, and if you ask nicely, they will go out of their way to help...."