No pictures, but it was (briefly) warm enough today to open up the hives and take a quick look. This was the first day we've hit 50F since October. Executive summary: we're 4 for 4 so far, with ample stores of honey on all hives.
I shoved some fondant into the two swarm hives; they are our weakest, since they were started late last summer. I didn't do anything more than open the tops, confirm there were live bees in each hive, toss in the fondant, and close them back up.
Eleanor's hive had a bit of mold on the inner cover, so I added some spacers to improve the airflow. Airflow through the hive is very important because the bees stay warm by balling up, eating honey, and vibrating. They keep the hive interior 80F in winter, and 92-93F in late winter when they start raising brood again. The moisture from their respiration can build up if there is insufficient airflow, and can actually cause ice to form on the inside of the hive. The technical term for that is 'bad'.
When we get a warmer day we can take a closer look and get an idea of the size of the bee populations in each hive. We're expecting to have to split Louise's hive to prevent them from swarming. But that will wait until at least May. Today was the last warm day for the foreseeable future.