Re: pile of dead drones
We've also got cold weather moving down from up north. The bees are cleaning up and tossing out the drones after the swarm and with colder weather coming in. With warmer and then colder weather patterns in the spring, bees will build up during warmer spells and then toss drones or larva when the colder weather moves back in, for efficiancy in clustering warmth. You're doing fine, just check on them in a couple or three weeks, after the weather turns warmer and they've had a chance to get your new virgin mated and laying.
20+ years, raise my own queens, feed when needed, I treat but have not perfected varroa management yet.