I was mostly kidding, but no, CF wouldn't be able to handle that many concurrent users and I imagine it would take a lot of refactoring to get it there. (Un?)fortunately, I doubt that's a problem we'd ever have.

CF could probably scale up reasonably well by throwing more hardware at it, but ultimately it's a single-threaded TCP server from 1994 that has been optimized for having a massive inventory of features over any kind of performance. I wouldn't enter it into any races.