That seems fair. What I was mostly trying to get at was a way to describe Santa without admitting his existence; for instance, I could say, "Santa wears a green coat!" and you'd be able to say, "That's wrong!" without either of us ever claiming that Santa actually exists. In other words, we would be communicating information about N, but not S.

More generally speaking, this problem usually arises whenever a word has more than one meaning, and information about which meaning is being used when is conveyed through context. As usual, discussion of the meaning of words leaves out a lot of details about how humans actually communicate (for instance, an absolutely enormous amount of communication occurs through nonverbal channels). Overloaded words occur all the time in human communication, and Santa just happens to be one of these overloaded words; it occasionally refers to S, occasionally to N. Most of the time, you can tell which meaning is being used, but in a discussion of language, I agree I was being imprecise. The concept of overloading a word just didn't occur to me at the time I was typing my original comment, for whatever reason.