Just a note for those of you who may be in a similar situation. YMMV.

If you have a couple of very large folders (even 1 TB or more) you care about holding onto from your unlimited drive, share it with a few (even throwaway) personal Gmail accounts. Once my HS disabled access to my account after I graduated, the school admin account somehow inherited these folders (the organization name is the new owner).

I still have access to these many TB large folders many years on in the “Shared with me” section of gdrive.