Yeah seasonal/holiday based towns don't really seem to work out. However, snowtown was pretty awesome last Christmas with the sledding hill and the visiting santa thing. The main problem I've seen with Classic and Era is the seasonal based events. The gifting system was amazing but now it can't be accessed, and some other things were interesting.

I still don't think that's why deadwood and snowtown failed though, it is most likely because they both require a lantern or draisine, and deadwood contains dark lighting as well as annoying effects that cause bad framerates.