Is it going to be just adults or kids and adults? Are you based in a TS in Hilton Head and doing day trips or are you staying in a TS in Charleston and doing Savannah for a few days.
Our family will be in Hilton Head that week and I have been grouponing day trip activities to Charleston, Savannah, Edisto Island (where we are stopping for a night on the way down) and to Hilton Head itself. There are walking tours, trolly tours, ghost tours, kayaking tours, dolphin tours, etc.
I'm trying not to over plan. They have a deal where you can try Groupon VIP free for 2 months that lets you get access to offers that have expired but not sold out. It also lets you have extended time to refund if you don't use the groupon.