Flying in the teens is certainly abnormal. I’m assuming your hive is pretty warm for some reason? Agitated? Super insulated maybe? I’ve had snow drones in healthy hives many times, but they don’t normally fly in the teens unless the hive is excessively warm. Hives will also heat up is they’re agitated by something; blocked entrances, mice, etc. Its a good idea to look for an obvious problem like mice or blocked entrances.
As for the dead queen, I wouldn’t count the hive out yet. I’ve seen a queen abscond from a failing nuc and try to get into another hive. Could be something like that. Not much you can do about it now until spring.