I have a swarm I caught back in the Spring that Iíve struggled with. Went from losing Queen, to a laying working, and now with a strong Queen/Hive. 5 frames with lots of capped brood and soon to be packed. My question is do I leave this Nuc alone, move to 10 frame, or even split? Itís still very hot in my area and I would think drones are still abound for mating. This will be my first winter for me with bees, so lots to learn as usual.
Even up here in Illinois bees will sometimes swarm in the late Fall. If the nuc is packed now and has lots of brood you could easily get a swarm. At least put another nuc on top to give them some room to expand. That will give you time to consider options.
I wouldn't know how much nectar they will have available in Miss. in winter or whether they can stand to be split this late. I got a new queen this month from a hive that had gone queenless, so it isn't impossible.
Personally I'd add another 5 frame box, with drawn comb if you have it. Feed the dickins out of them. They survive well if healthy, and mite free. Feed asap, as you need this capped before cooler weather sets in though. I love my nucs. I stack em 3 high into winter. Do great here in North Bama