Georgia polling being off by this much would be new, it's important to remember that. That's not to say it can't happen, but this poll (even though it's Quinnipiac) shouldn't be discarded the way it should if this was a Florida poll or a Rust Belt poll.
Even if Warnock wins, which is honestly a bit more likely than not as we speak, I really can't imagine the margin being more than 1.5 or 2 pts. Even then, the poll would be way off (for sure, people care less about polls being off margin-wise as long as they get the winner right). This margin would even be unbelieveable in a 2nd Trump midterm.