Several things should be kept in mind when planning, as
@bdtex has indicated. Logistically speaking, it has so far been preferable to hold these in a single location with well-stocked amenities like a central hotel or large, modern motel and nearby restaurants capable and willing to host a dinner. (Not a banquet or anything formal, but that can easily consist of 20-40 people.) It's easy for us retirees to find the time, but not all of our members fit into that category, so an approximately three-day weekend works best - if others are of a mind, they can come earlier or stay longer than that. The bus trip was strictly the quickly-taken-up offer by
@Eric Wittenberg to follow Lee's retreat route from Gettysburg to the Potomac and Falling Waters Battlefield and took the greater part of a single day; other activities were on the Gettysburg battlefield itself. Also, a competent and willing coordinator is mandatory for working out the details of whatever it is we decide on;
@War Horse , Bee,
@bdtex ,
@lelliott19 ,
@ucvrelics , and likely others I'm leaving out have done wonderful and time-consuming work toward making at least the last two a success. Another related need would be members willing to make presentations at various locations.
As for your particular suggestions, I haven't been there, but would suppose that Bentonville would be the likely location for a Carolina Gathering, assuming it meets the above requirements. Atlanta of course offers a wealth of possibilities, but suppose the most likely would be the Marietta area with its wonderful Confederate and National Cemeteries, Kennesaw Mountain NBP, and Civil War & Railroad Museum at Kennesaw.