The biggest consistency I've heard is this:
There used to be either a jungle in Cyrodiil or Cyrodiil was jungle, either way, Tiber Septim CHIM'd it away for the Red Legion. TES:O takes place before Tiber/Hjalti's birth, so Cyrodiil should have a jungle, right? Well I don't think it will.
Or I'm completely wrong and babbling. If I am, please let me know.