Obviously a functional site would be optimal but if you can’t hack it, well, figure out another stratgey. You can show static HTML, screenshots, half tied together page design, damn, even drawings can work. People–who happen to be investors–love things that they can actually conceptualize, visually.
Next time, start the pitch with, “Let’s get right into it and show you a demo,” it will make all the difference in the world–trust me.