Good morning Mr. BenFramed.
I have seen hives over winter drones. Kind of a rare event, it happens contrary to the norm.
The question regarding breeding quality of the overwintered drone. I have not seen any research that addresses this question. I will provide a summary of research I have studied regarding breeding viability of drones.
Viability of drone spermozoa is reduced by summer heat when a hive is subject to extreme temps from direct sunlight. Temperature studies suggest that all semon is sensitive to heat, mammals to insects. A drone in a hot summer hive is still of breeding quality but not as full prime as a drone not exposed to heat extremes.
The spermatheca, holding sperm sack, of a queen actually provides nutrients to maintain viability of the stored spermatozoa thus lasting the queen for years. [I just read this recently] Thus most semon can cryogenically be maintained at -80F for ,,,, well,,, the time is unknown. Honey bee spermatozoa require special conditions for cryo that were recently discovered allowing cryo storage. Dr. Colby, bee geneticists, ships semon via the mail, very successfully I might add. In summation, heat is a factor affecting the breeding quality of a drone. So, an overwintered drone, although not specifically studied, the data suggest the drones should be of quality the following Spring.
Blessings
Van