While we have been to HH during every month of the year, I have never experienced (yet) the island over the Christmas Holidays.
So, I contacted Chef Gordon at the resort. He has been a HH CM since before the resort opened in March, 1995 and is a wealth of information about the resort, the island itself and the Low Country in general.
Here are his comments about Christmas at the Hilton Head Resort:
"
Christmas is a great time on Hilton Head, and at our resort! On property, we have many different holiday themed programs, including arts and crafts, story time, carolling around the resort, and even a visit from Santa Claus! Around the island, there are many great things to see and to do. Some favorites are going down to the Coligny/North Forest Beach area to look at all of the lights...they really go all out down there! The Lawton stables in Sea Pines does a living nativity scene during Christmas time, and they also have sleigh rides. All of the fire stations on the island have a friendly competition among themselves to see who can decorate their station the best. It's for charity, and the winner gets nothing but bragging rights. Almost all of the shopping areas will have some beautiful decorations, and most of them will have "open houses" during Christmas week, when they stay open in the evening and serve wine and cheese or some other snacks. It's a great way to converse with local merchants. The vast majority of restaurants on the island remain open on Christmas, but it's a good idea to call ahead as many host private parties and/or have special (smaller) menus than normal."
He added that he can usually be found working at the resort Mercantile and he really enjoys chatting with guests. Be careful about asking him about local restaurant suggestions though - unless you have a LOT of time.
He is a gourmet chef and used to offer "A Private Affair" program at the resort where he would prepare a private meal for small family groups in a GV before the resort sold out and later at the Beach House. He really knows food and is always happy to offer dining suggestions. Be sure to stop in at Mercantile and ask if Gordon is around!
I hope this helps!