If Warnock holds on in GA, I'd think Dems would be favored to hold the Senate. If Warnock wins by this margin (unlikely), I'd call it a certainty.
I disagree with this — I think Democrats are more likely to lose AZ/NV/PA (and obviously WI) than GA in the Senate. Agree on the second point, though.
I think they'd be likely to flip PA on a night when they're retaining GA, so a loss in AZ would be fine (although obviously not ideal). NV I feel would be a true tossup in this scenario.
Still, the fact that we're considering Democrats holding the Senate at all is a testament to how bad the GOP's swing state recruits have been.