I don't have the 300GB on my SSD.
But somehow my Core is synced and up to date.  I've been running Core since 2014, I've never run into this before.
It still took almost 2 full days to catch up and sync each of the times I've done it over the past couple weeks
So how best to proceed?

Uninstall & reinstall Core and delete the entire AppData\Roaming\Bitcoin folder & do it yet again?
What do I need to do with Armory either before or after I download the whole blockchain again to get it to read or run Core itself so it can go Online?

Thanks