In answer to my own question...
While attempting to hot tighten, I had the parts laid out and plugged in, but not assembled inside the print head when I got the error.
In desperation, I assembled the print head on the printer, and then started up printer. Found Home, raised the print head 60mm and over on the X axis until I could fit the wrench (about 150mm or so). I raised the temperature and no error thus far.
Lesson learned, hot tighten on the TAZ 5 fully assembled.