Thanks everyone for the good advice. Here is an Update
We had some warm weather again today so we did another inspection of the troubled hive. There was some good news which was encouraging, but further mystery surrounds this hive.
First, we were all prepared to take the upper deep and push them down to just one deep for the winter, but when we opened the hive, we found good news - HONEY and lots of it. Mysteriously, there were now several very heavy frames completely capped with honey in this hive. I would estimate the upper deep at 50%-60% capped honey now! The frames that weren't full, were being worked furiously to store necter and get it capped. Here's a photo of one of those frames not yet filled:Full Size Image
The mystery goes to the source of this new found honey. The top feeder was still full and there were almost no bees feeding from the syrup in the top feeder. Where did they get all these new stores? Maybe they stole this honey from somewhere else?
We did see a number of dead yellow jackets floating in the syrup. How they got in, is also a mystery. Perhaps this is what made the syrup unappetizing for the bees? We cleaned it up and removed the dead yellow jackets, but left the syrup. Here is what that looked like:Full Sized Image
Finally, we did see some brood and larvae in the upper frames:Full Size Link
We also saw the queen on one of the brood frames, but didn't get a photo this time. After all this, we decided to leave the upper deep and keep feeding. I'm a bit more hopeful they will make it now. I also saw one stray yellow jacket on the frames while we were inspecting and one later on the hive cover after we closed it up, but how they got into the hive-top-feeder has us puzzled. There were some small cracks between the frames, which seemed to be attracting some attention from the outside. Perhaps the yellow jackets were squeezing through? To make sure that wasn't happening, I sealed the cracks with some duct tape. More news later as this mystery continues.