I am going to try to answer these all at once. It helps to understand that colonies shrink as winter approaches. First, the drones are forcibly removed, which reduces the population by 15 to 25%. Then, the number of workers is reduced by attrition: when workers die, only some are replaced.
The colony has a limited amount of food to get it through the winter, so extra mouths are a real burden. The amount the colony shrinks is dependent, among other things, on the race of bee. For example, Carniolans are known for overwintering with small colonies, while Italians go into the cold months with much larger populations.
When the brood nest first starts to shrink, brood may be somewhat scattered. This is because after the brood emerges, the workers fill the cells with honey or pollen, causing the nest to get smaller. It takes a while for all the outlying brood cells to empty, but once they do, those cells will be filled with food as well. So a situation where “the brood nest is really small and the capped brood is all spread out” sounds normal. Look again in a couple weeks and it will likely be more compact.
As time goes by, the nest gets even smaller and more compact. Usually by October or November, the brood nest is a fraction of its summer size. The DVD-sized nest mentioned above is probably perfect for this time of year. Sounds like a go. By the end of November, the brood nest may shrink to nothing for a few weeks.
On the other hand, it is not unusual to find hives with failed queens in the fall. For some reason, a certain number of colonies do not requeen successfully after a summer swarm or supersedure. If it happens too late in the year, there is no chance for successful mating, even if a virgin queen can be reared. So if your “brood boxes have no eggs and no larvae and almost no honey,” it is time to think of combining.
In colder parts of the country, an October supersedure queen isn’t good for much. If your “supersedure queen can’t mate,” she can only lay unfertilized eggs (drones) and the colony will soon collapse. Again, it is time to combine.
If your queen is “walking around in empty supers,” she is probably just out for a stroll because she doesn’t have a lot to do right now. You’re good to go, just make sure you don’t inadvertently lose her, move her, or kill her. Expect the unexpected with queens that like to ramble.
But if your queen is head-down in a cell? That doesn’t give me a warm-puppy feeling. Queens will often measure the width of a cell with their antenna, but if a queen is content to spend time with her head in a hole, it may be time to combine.
If yellowjackets are freely trekking in and out of your hive, it is probably too late to do anything. Yellowjackets eat brood, adults dead or alive, and honey as well. Open the hive and see if anything is left. Don’t combine a ravaged hive with another until all the yellowjackets are gone.
If bees with no stores will not take syrup, combine. The colony is probably too small or too weak or too cold or too demoralized to save itself. As beekeepers, we like to think we can keep small colonies alive if we feed them, keep them warm, protect them, or coddle them. But there comes a point when it is better for everyone to cut the losses—both yours and theirs—and move on.
Now, all that preaching reminds me of what? Oh yes, time to combine numbers two and nine. I keep thinking I can make a go of number nine, but who am I kidding?