Ok, my $.02. Moving around is a great idea. I like the idea of going to different places. Now, if you decided to go the Chattanooga or Pigeon Forge route, I can offer some help as I spend several weeks per year in both locations. For what we do, Pigeon Forge is probably the best location. I don't think there is a single cabin that would hold everyone, but I have stayed in a cabin complex that would easily house all of us and give us a place to be away from the crowds and probably not have any issues with train horn installations and the like. Cruising would be easy and fun, lots of places to eat, lots of things to do for those who want something not Av related, etc...
Just got back from Chattanooga, and believe me the Southern Belle would definitely hold all of us! The food was great and the cruise down the river is SPECTACULAR!!!! Don't know about what hotel would be best there, everything is so close and not very many parking lots. The Choo-choo would be OK, but I think that is a little over-rated as far as hotels go.
If you decide you need any info on the area to help in planning for either, let me know.