Demons.
I chased a similar thing for a year (almost identical symptoms, including the realtionship to temperature). Finally thought I had it licked by fixing a bad connection at the fuel pump, but it has since returned with the cooler weather this fall. Mine is definitely not as bad or regular as yours sounds. Its an annoying hesitation only while warming up and only occurs every few days. Livable, but still annoying.
Mine threw a throttle position sensor code. Even though it tested OK I replaced it. No difference. My CPS and ECU have been replaced as well. I know it doesn't help you much at this point, but if I can figure it out, maybe it will solve your problem. Oh, I just discovered a disfigured coil pack (the plastic around the connection to the plug is dissintegrating. I may get a new one and see if it helps.
Dave