Ok, first, your Stat will have nothing to do with the temp of the incoming air. The IAT senses the intake air temp in order to guess at the air density coming into the intake. It works hand in hand with the MAF. Colder air is denser (better) than warmer. Hence the need for a CAI! If the air density increases, the PCM can deliver more fuel to keep the A/F ratio correct. This should translate into more power. Now, while all this is going on, you have an O2 sensor in your downpipe, and it'* trying to keep your exhaust clean. It'* looking for unburnt oxygen coming from the combustion chambers. If you don't get a clean burn, it adjusts your A/F ratio. Now, how much oxygen is left after the burn if you've tricked the intake? I dunno. I can tell you that it will run a little rich, but whether or not the car can compensate and nullify this through other means is another dunno.
I can tell you that you probably will see some slight gain. Every little bit counts, right? If I were to try this, I'd install a resistor in series with the IAT to lower the indicated temp slightly throughout the range of sensing. Installing a fixed resistor to tell the intake that it'* always 60° outside will only gain you power at certain temps. Keep in mind relative humidity increases also increase air density. Not to complicate things, or anything.