Flying on 3 or 4 cylinders

I had to cancel a flight today because one of the plugs in my Mooney
doesn't seem to be firing (tried to burn it clean but no luck).
Anyway, it got me wondering what would happen if you lost both plugs
in a cylinder during cruise (certainly take off would suck). I often
cruise around in my Mooney at 45% power (as indicated on the EDM). I
would like that I would have at least 45%, right? I'm not planning on
flying with a dead plug but really just an academic curiousity.

-Robert