Wound up answering my own question by trying it. I wasn't able to budge the tip when cold, probably because of residual filament gluing it in to the hot end. So, hot it is.
Two challenges in this process:
- The provided nut driver is deeper than the tip is long, so you have to hold the nozzle tip with something else (like your fingers ) to start it threading in to the heater block
- a metal crescent wrench holding on to the heater block conducted away enough heat to trigger a thermal runaway shutdown.
Fixes for these do come to mind... I might try milling a wrench out of wood and gluing a nut in the bottom of the driver to take up some of the depth.