If you have 70GB free on SSD, maybe you could copy it to SSD and do the upgrade and syncing on it instead? The fresh full sync is only 50GB at the moment, but since you are upgrading from existing full node, it might grow to 70GB.
Yeah... I'm not so "storage space poor" right at this point in time... so I installed 3.0.3, started it up to create folders etc on the main SSD drive and then shut it down. After it was shutdown, I copied over the files from the old HDD storage to SSD, then started Obyte back up.
At that point, I got two messages.
The first was that it was updating the database and would take hours... the second was mostly obscured by the database update message, but eventually I deduced that it was actually a "fatal exception" about using an old backup or keys from another device... when I clicked "OK", the wallet shutdown.
I restarted, and it gave me the "updating the database" message again, but no exception... after several hours, it finished, showed all my old balances (including BlackBytes and the probably defunct TitanCoin and SilentNotary tokens) and is now currently syncing away:
I might symlink it all back to the HDD once it has finished syncing. Will have to see how much SSD space I have left after it's all done.