You also can't make a transistor out of a single atom. The fact that you need doped silicon to have a semiconductor rather than just silicon as an insulator means that we'll be cut off well before then. A ~50x reduction in feature size (so that's 6ish nodes of shrink) is about what I've heard about industry expectations.
That being said the future never ceases to surprise.
That being said the future never ceases to surprise.