It really depends on the strength of the CAD. I brought up about January 2005 last night. We started off in the mid 30s with sleet and spent most of that event in the mid to upper 20s. However, even a weak CAD definitely affects the immediate Atlanta metro area. It doesn't always guarantee wintry precipitation here, but the likelihood is very high. It doesn't even have to be the Winter season, I can't count the number of times CAD has saved Atlanta's butt a lot in severe weather outbreaks also.
EDIT: I think the HP in the January 2005 ice storm was only in the 1020s or 1030. If we have a 1030 or higher HP anchored to our NE, it'll most likely get the job done down here. Anyone know a good website to find archived surface analysis maps from that month/year. It was an end of the month storm, I think around 28th-29th. I know it started on a Friday afternoon and went through all of Saturday.