Janet if your daytime temperatures drop below 50 for days at a time during the winter the bees will be in a winter cluster until it is consistently above 50 again. If they go into a winter cluster then yes, the drones are expelled or killed in order to have more food for the workers and queen.
I would contact the beekeeper about the fewer numbers you are seeing and tell him about the ones flying around the light at night time. If you don't mind peeking under the outer cover to see how many bees are in there then do that before you call him. A hive going into winter needs to be as large as it possibly can be though there are some breeds of honey bees who do downsize their numbers for winter. Ask your beekeeper about the bees you have. Beekeepers love to share their knowledge to anyone willing to listen.
There is a new threat out for honey bees called Zommie Fly Parasite which makes them fly around lights at night time.
A good beekeeper will always want to know if there's a possible problem at a hive no matter how many he or she has to tend.
