I successfully finished probably what you will need to do - here is the description of such process.
It’s simple process after all - but requires a functional internet connection and serial console connection (fortunately port is physically the microUSB).
I do believe it can be done within an hour or so.
If one does such migration, it’s about time to change the SD card anyway (if the Turris 1.X running from it for quite some time) for the fresh one.