My mistake. It is more dense. How significant depends on the amount of cooling. I can tell you by experience that 30-50* F cooling is not out of the question by any means (and may even be conservative based on my experience with methanol injection on turbo cars) and is an incredible difference in power.

Elistan is correct, timing and compression can be higher. Since, as far as I'm aware, compression is not variable in the F1 engines, that brings us back to the engineers being able to advance the timing more and possibly lean out the fuel mixture more based on lower intake temps.

Unfortunately, I have more practical experience with this than theoretical experience. Watching intake temps go down even 20* on an NA car is an impressive gain. Watching them go down 100* due to methanol injection (basically doing exactly what the F1 boys are doing - misting the fuel mixture into the intake path) is almost unimaginable. It transforms the potential of the engine.

 

Thanks!