Except followed by a subject pronoun

I know everyone believes that "except" in some cases is a preposition and as such is followed by an object pronoun, with the classic example being: " Everyone enjoyed the party except me ( not I )."

However is it possible to argue that except is also grammatically a conjunction and is able to follow the same rule that governs the use of "as" and therefore can come before a subject pronoun.

For example: He is taller than I. than here is a conjunction and there is ellipsis in this sentence.

Cannot except be used in this way also?

Everyone enjoyed the party, except I ( didn't enjoy the party )

I've always wondered about this, but there are no definitive answers on the web.