Hey neighbor! I know exactly where you are and have taken that route part of the way quite often to Charlotte and a couple of times home from Hilton head that way. Here's what I can tell you: Its about 6 hours to Charlotte and then another 2-ish to the 95 past Columbia. Friends in Charlotte told us it takes about 7-8 hours to get from there to Orlando. The traffic is pretty great, with the exception of the area immediately north of Charlotte, which can become a parking lot at the wrong time of day. If you want to stay overnight in Charlotte, I would reccommend that Courtyard Marriott in Ballentyne, or if you need a villa, the Staybridge Suites also in Ballentyne area. Its a smidge off the 77, but both places are nice and safe.
Now when we drove to WDW, we took the 95. It took us about 16 hours and was a pretty good drive, so good that we drove straight through on the way down. However, we wouldnt do it again, because we felt really jetlagged about the second day at WDW. The plus to this route is that there is a fantastic website that can tell you what is at every exit along the 95 between here and there. So around lunch time, I could look at myt list and say, "ok gang either we stop now at BK or Subway or we wait 10 miles until McD's...." That site is called usastar.com