Got the RV running in time for Spring Break. I'm a happy camper. Thanks everyone.
I had also called Winnebago and Rod in the service area said the same thing. He said that I'd have to clean each of the various connections starting at the battery and follow it toward the starter. This
post sums up pretty much what I did. My plan was to test it as I went. Hope this helps someone else with their ground problem. The description at the beginning pretty much sums up what likely happened to my battery. I love step #9.
Anyway, I started at the battery (I have terminal posts) and these type of
connectors that allow me to use side mounted battery connectors with it. It turns out the connector for the negative terminal was stripped on the inside so the terminal screw wouldn't make a good connection. It seemed good, but it obviously wasn't. I pulled off the connectors cleaned them with my plumbing pipe cleaner tool and cleaned the inside of new connectors I bought and voila, I had headlights and it started right up!
It also appears to have resolved some fluctuation I was seeing in my speedometer...the speedometer would float up and down and all around. I haven't taken it for a long drive, but just driving slow, it seems to be working better.
Thank you all for your quick responses.