Raleigh to Charleston shouldn't be a big deal if you have an LR 3. I recently went from D.C. to Folly Beach to visit friends and was fine. It's only 65mi from the Santee SC to Folly, so downtown Charleston is a chunk closer. I agree they're overdue for an SC somewhere in greater Charleston however.
Also, I think the parking garages in Charleston have standard non-Tesla HPWC that are free while paying to park. I hear they fill up quickly, but it is always an option. If you charge for two or so hours and walk around downtown, you surely have enough range to get back to Santee on the journey back. There are also EVGo and Electrify America stations close to charleston. If you have the Chademo adapter that is always an option.
But at the end of the day, there needs to be a supercharger in Charleston. They have been saying it's coming for far too long. I find it very hard to believe they wouldn't be able to find a host, so I am wondering if it has something to do with the local government and permits.