Apple ID changed, can't unlock device

Short Story...

Got me an iPad mini a few years ago. Loved it until it got a small crack on the screen. Bought me an iPad Air 2 last year and retired mini. Still loving it, and no cracks!

Couple months ago, I had to switch ISPs. Because that means a new email address, I had to change my Apple account info. Took a bit of wrangling to get it all switched, but got 'er done.

Then I happened across the iPad mini in my junk drawer the other day and thought, hey I should give this to someone that can use it.

Problem is that I still have some files I must retrieve from the memory before I can wipe back to factory settings. It's asking me to sign in, but the account it's inquiring about no longer exists. Basically, since my Apple info has changed. I'm unable to log into the mini to do a backup.

I've tried to restore but does not help. However, it should now have the most recent iOS installed.

Please! Is there anyone that knows how to fix this, or at least a work around of some kind to save my drawings/writing?