This all sound like battery conditioning to me. The high RPM could be the battery discharging with the small generator turning up the ICE. This would also explain the ICE not going EV at stops. The system most likely continues with a fast charge which heat the battery and causes the battery fans and maybe the A/C compressor to run. My guess is, Ray does not drive EV only till the battery is low enough. Not having a battery level may cause people to forget about driving in EV whenever possible.

Ray, are your tires up to 44psi to promote EV driving? With your outside temp that low, you should not need that kind of battery cooling with normal driving. If things don't get back to normal real fast, you've got other problems. With no trouble codes, I lean to battery conditioning like TeeSter

GaryG