I reside in the area that you referenced as being the "sixth" region. In fact, my location is sixty miles SE of Macon and I can assure you that even this far South isn't devoid of winter weather events. During the last decade, we had four separate occasions that met the criteria of being some type of winter storm. While I absolutely do not expect to see snow/sleet/freezing rain every single winter, it is absolutely not correct to assert that anyone south of the cities you listed under number six to see wintry precipitation during any cold weather month. The old rule used to be that any time there was snow breaking out between the I-10 and I-20 corrider in Louisiana, that the chances of it making it to the Southern half of Georgia were extermely high in terms of plausibility. However, that is no longer accurate and I think that anyone south of Atlanta in Georgia and the lower half of South Carolina (excluding those that got crushed in January 2018) has a right to complain about how things have turned out lately way more than most. If one wants to truly draw a line in Georgia in which your chances of seeing some type of frozen precipiation dramatically drop, it would be a SW to NE line from slightly below Albany to Tifton to Baxley and upwards to Statesboro. Anything on the other half of that line most definitely has a chance at seeing at least something measurable each winter.