nevermind... I screwed up the install and replaced my config-inc.php file with the new one (with updated settings) prior to running the upgrade.
For reference, to fix it, I had to:
- replace my old config-inc.php file
- re-run the upgrade482.php file
- put the new edited config-inc.php file back
I can now access the admin panel. I'm still having the cookie issue, but that's not a big deal for the moment.