Not a warm destination but you can hop out to Spokane, WA (GEG) the first weekend of December. ATL-SLC-GEG on 12/5 and GEG-SEA-ATL on 12/7 for $318. Factor in that you'd earn at least ~4,500 RDM, pretty good deal. Hit up some skiing in North Idaho or just enjoy Downtown Spokane.
(worked there the last 3 years and enjoyed the weekends there in the winters)