We used to get it like that all the time -- before early arrivals. Right as the park opened, we'd often be the first people through a few of the houses. Then right before closing, we'd get it that way again. Those days are long gone now, though.
Personally, I miss the really old scare zones that weren't crammed with people. It was just lots of fog and tons of scareactors. It was damn near impossible to see.