Only announced Christmas Dinner plans I've heard of is Martins Pitstop on the afternoon of Dec 25.
"The Pitstop Café will be having a Christmas Lunch on the 25th of December at 2.00pm. Three courses including Roast Turkey with all the trimmings. Limited number of covers available, so please book early to avoid disappointment. Cost 499 Baht. Deposit of 200 Baht please with booking."
Martin joined Colin last year for a Christmas Bash