There is a block off North Forest Beach Drive where the residents do a phenomenal light display. I can't remember the name of the street but if you drive north of Coligny Circle and look to your right toward the beach,
you can't miss it. I know they also usually have a living
nativity at the Lawton Stables on Sea Pines Plantation.
I believe the afore mentioned Festival of Trees at the
Hyatt (now the Marriott) is earlier in the month of Dec.
prior to your arrival on the 23rd. You're right about the
weather in December. We've had a Christmas where we
ran the air conditioner and then there was last year
where the low temp was 23! Pack a pair of shorts and
also a winter coat! Have fun.