The last time I saw such an intermittent electrical issue on a car was on my Dad's old Dodge truck. We checked things for hours and finally brought it in to a shop. The mechanic sat in the drivers seat, poked a couple things with his scanner probes, then just thought for a minute. Finally he just nudged the ignition switch on the steering column, by turning it just the tiniest bit, and the problem (bad idle and no dash lights) instantly vanished. Then he moved it back again, and the problem came back. Move it back to the good spot, problem gone. Etc. He changed the ignition switch that turned out to be just worn a little too much and that did the trick.
I don't know if it might be the ignition switch, one of the fuse boxes, or somewhere else that might have a bad connection, but I'd suspect every component that carries voltage for more than one function/multiple different functions. It might be something as simple as a bad ground connection in the wiring someplace.

 

Update-Alternator arrived, installed today. What a PIA! Took for a 20 min drive while monitoring voltage on a graphed scanner. Stayed consistent at 13.5-13.8. Had high of 14.1 and low of 13.4 in that drive. Nothing funky happened, but time will tell. FYI, the alternator on an AWD car only has 3 attachment bolts. There is a large crossmember under the alternator so all work has to be done from above as opposed to a non AWD version.

 

Hoping it's fixed for good!

 

Just a quick note to close the circle on this for future reference. Have driven the car a couple hundred miles without a hiccup. Problem seems to have been solved. In 40 yrs of working on cars, have not run into this issue before. As in, with car idling, voltage at battery was all within specs. Battery light never came on in the instrument cluster. Probably should have monitored the actual voltage while graphing during a typical drive, but didn't. With Boykie help, decided to replace the alternator. Went to Rockauto, rebuilt Denso. Hoping it lasts. Onward and upward!

 

Awd models have 4 mounting bolts, if you only have 3 then your alt has been changed before and whoever did it was just to lazy to install the lower rear bolt. Probably the dealer.