Ah ha ! yup, that’ll do it.
Ok, I get it now. I saw you were severeal versions behind, so i knew a nuke and pave would ultimately be the best choice. As for drives, I keep a bunch of old drives /buy some real cheap for the sole purpose to serve as “stand in” drives during migrations or to host configs and files if my large drives are nearing capacity.
I wish i would have been around to help the process for you. Also, buying old drives (old hdd’s from thrift/ leftover Corp installs) can serve as cold storage in a pinch. Encrypt the drive, and only hook them up when you need the data or space.