If the political climate were such that the D’s could pick up 12 R seats in the Senate, I’d think there would be a reasonable expectation that they wouldn’t lose any of the 13.
Heck, to get to 12, you’d probably need McConnell and Graham deciding to step down, and MAGAs winning the primaries. It’d be more likely that the political climate shifts such that moderate R’s took their places (or they stick around but be willing to convict).
When we’re that deep into improbable scenarios, anything becomes possible (albeit still very, very, very unlikely).
(And now it looks like my query has finished running, and I need to go choose among a couple of options of what I want a tail to look like out at a 1:10000 return period.)