Still alive and kicking!
When I got to the hive, I noticed a couple new dead bees on the landing area. There had been a few bees on the way to the hive, on the fresh snow. I pulled back the fencing I had put around to discourage critters, removed the styrofoam and wood blocks from on top of the telescoping cover and lifted it. I was very surprised to see 50 to 70 bees crawling about on top of the inner cover! There was a small pool of water near the slotted opening of the inner cover. My guess is this is from water that has moved up through the hive, condensed in the cooler air on top of the inner cover and possible had been frozen in cooler temps. Bees were getting much needed liquid nourishment from this. Satisfied that I did not have a "dead" hive, I quickly closed things back up. I tried tipping the entire hive to try to determine weight but it wouldn't budge. I take this to mean it still has a lot of weight to it, which would be good news.
The temps are to plunge again mid-week next week, unfortunately. After that, I hope for warmer weather so I can again resume some feeding. I am feeling much better about things, especially since I read about a number of people losing their only hive. Keeping fingers crossed.