I am about 80 miles north of the Gulf. I run a 2 box brood nest, with 1 Deep and 1 Medium. Some colonies have a 3 box brood nest with all three boxes being mediums.
For me, feeding in the Fall is always on an "as needed" basis, but more often than not, some colonies need some help before winter.
As a general rule, I want the top medium box in either of these configurations full of honey/syrup going into "winter." That is usually more than adequate, though you will need to check in the spring and make sure they do not eat through it all before the nectar flow starts. If I don't have a medium box full of honey, I will feed them in the Fall until they pack it out. I don't know what your flow looks like over there, but I am guessing the main nectar flow has been done for some time. You may or may not have a goldenrod flow coming in the Fall, but I have learned that I cannot depend on goldenrod. All of my yards seem to be doing fine so far with the exception of a new yard I started this spring. I put 2 gallons of sugar syrup on all of those hives this weekend. I will do another food store check in October and feed more if I need to.
While I believe you can certainly overfeed in the Spring and get some negative consequences, it is a lot more forgiving to overfeed in the Fall. So, if in doubt, feed your bees. They will not take it if they don't want it. Feed them carefully. Do not use front-entrance (Boardman) feeders and try not to spill sugar syrup all over the place. It is robbing season.