Ok, so I tried it last night with my existing Pi3 image. It didn't make it past the 1st boot (kernel) screen. I got a number of error messages such as these:
Recovery4.dat not found
Recover.dat not found
startup4.dat not found
Then there was another message stating that this Pi needs an updated version of the software.
Is there a way to do the update of SD card offline by mounting it?