I live in Charleston and have driven to HH 3 times and it is always almost exactly 2 hours. From the airport, you would just take 526 towards Savannah - get off on 17 south and take that to I-95. It's about an hour on 17 to I95, about 30 minutes to the HH exit off 95, and another 30 minutes from the exit to the resort. You can also go through Beufort if you want to avoid the interstate and it still takes the same amount of time - it's just a little more relaxing and scenic.
we're going again in October and staying with friends over NYE!
Have a great time!
