Is one molecule truly the limit? Certainly it is as long as we view the various components of electronics as discrete objects: you can split a molecule, but this results in smaller molecules (of different types, but molecules all the same), so miniaturization becomes a race to see who can make the smallest molecules act as the different kinds of components.
But the integrated circuit allowed for many components to be combined into a single discrete object. Does physics allow for the possibility of doing this on a molecular scale: a "molecular integrated circuit", where individual atoms within a molecule act as components that affect how charge flows through the molecule's chemical bonds?
Obviously, our technology is not at the point where such a thing could be created. It may very well require molecules to be assembled atom-by-atom. What I'm asking is physics as we currently understand it allows for the possibility of such a molecule.