Once they have fully stocked their brood box with the syrup you’re feeding them, you can probably stop feeding them and take the second brood box off until the nectar flow starts (probably in Jan or Feb but you’d be better off asking locals like @Dawn_SD).
Because of your mild temperatures, the bees probably don’t ever need dry sugar or fondant.
Probably not necessary to insulate and most days the bees would be able to fly.
With those mild conditions I would just reduce them to one box and leave them. They will probably forage each day so as long as they have some stores there would be nothing to really do. Just check every now and then that they still have enough. If not, then give them some 2:1 but you are unlikely to need that.
Be ready to through another box on in early spring though because they will explode.
As @chau06 wrote, they shouldn’t need dry sugar or fondant. Don’t feed them pollen patties until about late January. You don’t want a population spike when we are in a nectar dearth (as we are right now). You don’t need to insulate, but you can if you want to. It won’t hurt, but they really don’t need it. The queen will most likely continue to lay throughout, just with reduced numbers until spring.
How much honey do they have in the brood box? How much pollen/bee bread do they have? They will eat about one frame of honey per week, if there is no nectar flow. I like my hives to have about 2 frames of pollen going into winter. If they don’t have that, definitely give them a pollen substitute patty in January.
Most beekeepers use double brood boxes in SoCal. If you don’t do this, then with our long nectar dearths, you are going to have to keep checking their food stores over winter and continue feeding. Don’t add a second box now, wait for the spring nectar flow in about March. When you see that the hive is strong and well-populated, with plenty of brood, add the second box.
Have you done varroa mite counts and treated? Varroa is very hard on single brood hives in the winter months.
Sounds like you are in good shape, and my advice remains the same.
Don’t worry about the capping, as honey often doesn’t get capped after about October. The reason is that the bees have to fan to dry the honey, and fanning blows nice warm air out of the hive. Plus wax becomes much harder to shape in cooler weather, so often they don’t bother with capping until things warm up. Plus, if they are going to need to eat it soon, why bother capping it?
Even though they have no visible pollen stores, I would not give them a supplement yet. Same reason as above. If you have capped brood, they have enough coming in to keep the colony going over winter, so you are fine.
The mite situation sounds very nicely handled. The only thing to do now is heft the hive from time to time to estimate the weight (i.e. honey stores). If it feels light, feed them with 2:1 syrup, as you have been doing. Open the hive as little as possible, unless you are worried about something. In that case, pick a warmer, sunny day, with very light wind, and be quick.
They must maintain a pretty high consumption rate (by flying and attempting to forage and raising brood?). Last winter when I was doing regular weights on my hives they consumed (net) about 12 lbs 10/20-12/20 and about the same amount between 12/20 and 3/20.
I forgot to say, most professional beekeepers in my region say that their hives require 45-70lb of honey over winter, and may require additional feeding even with that. That is why double brood is the normal standard.
Well, each deep frame holds about 7lb of honey. So a 10 frame with no brood or pollen would be enough. An 8 frame might not, and 8 frame with brood and pollen definitely would not. Hence our local guidelines.
So much useful information! My questions have been answered, and then some. I’ll likely read these posts several times over in the coming months. In the very least, it sounds like I need to procure a 2nd brood box for Spring.