You may want to have a look at this estimator:
According to previous months, you should be able to get your 2TB back in roughly 4 months.
This said, network activity has been quiet these days, so it may take longer… no one can really predict how bandwidth usage will look like in the future ^^
Don’t hesitate to start a fresh node now without waiting for your old node to fail (if it does), if you have 550GB of spare space somewhere. It does not harm to run 2 nodes behind the same IP. You just have to be careful not to mix up identities and port forwarding.