Over 50 degrees there isn't much the GPs are doing for you. You don't need them at all in fact...
For general cold weather stuff here's a couple of things you can do though, forget about the WTS "cycling". That light is on a sort of, timer. It is no indication of how long, or even whether
, the GPs are activated. Try leaving the key on for a full minute, then cranking. Also, in the cold your oil, because it's still a 15W viscosity, is adding to that effort of trying to start. In the Winter consider 5W-40 synthetic, 5W oil makes it easier.
So, you see cranking rpm on the tach and you're not having trouble with the engine quitting randomly, doesn't sound like a CPS issue. It does it at 50 degrees, I'm not thinking GPR (check though, here's a good link -> Troubleshooting GPR & GP's
Your "leak-down" theory sounds good and would be where I would start. The first place would be to remove the little plug at the top of the HPOP reservoir (allen key) and dip
the res (stick the longside of the allen) to find out how far down from the top the oil level in there is (should be @1" or so). If it's way down what can be happening is that the HPOP is draining dry overnight and you have to do a lot of cranking for the LPOP (engines oil pump) to refill first before it can produce the pressure needed to start.
After that, don't screw-around trying to guess, get it on a good scanner and monitor the sensors (ICP shows HPOP press) to figure out what's going wrong...
Also, might as well get this out of the way , you damaging your engine with that K&N AND the SuperChips isn't doing your transmission much good (if it's a Auto) nor are you getting what you should from it in programming. There are Much better choices for Both IMHO