Do to the limited local offerings, I thinking about going to the local computer store and picking up a small case cooling fan since I need it tomorrow morning. The size it perfect, but it is a 12V fan. I will be running a 2S (7.4v) pack and plugging the fan into the receiver. I'm sure there is no more than 6V getting to the receiver. So the question is, if I put the fan in the AUX port of the receiver, would the fan operate? I understand that at best it will be half speed, but will it work to at all?

Should work fine, I used to lower the voltage on computer fans to 5v all the time to make them quieter.

I would recommend to route it through the lipo instead. Not only will it free up the port but it can pull more volts thus creating more thrust. I'm running a yeah racing tornado fan straight on my lipo with no problems. Sounds like tornado inside my car.

Currently running a Rocketfish computer fan on my SCTE. Works, and looks great.

what are you cooling, motor or esc?

Did you ever do this? Has any one done this? I was contemplating this for the same reasons. My lrp fan died and cannot get a replacement fan fast enough.
Does anyone know the specs of the lrp fan? I bought a 12v but have not hooked it up yet.

A friendly advice, move it to the receiver since it won't keep working for much longer (from experience, with the same fan)