I told you back then where you were claiming that 'she has played it perfectly, and will force McConnell to accept her rules' that there is nothing she could do about it, and will send the articles without a deal with McConnell.
She played it badly when she rushed the impeachment. The subpoenaed should have been forced, instead of now crying how the Republicans don't want witnesses (which would essentially mean the Republicans actually trying to force subpoenas that Democrats in the house refused to).
Providing that McConnell manages to keep the Republicans united, there is nothing the Democrats can do. The hope is that Collins, Murkowski, Romney, and Gardner go against McConnell's orders (and Manchin, Sinema, and Jones actually vote with Democrats), but I don't know if this will happen (Romney is all talk (like Jeff Flake was) but in the end votes on party lines, Gardner can be a wild card, I expect both Collins and Murkowsi voting for witnesses assuming that the vote goes in the floor). Maybe the best we can expect is a deal from those 4 with McConnell to allow some limited witnesses. I also expect all Republicans to exonerate Trump, with Manchin and possibly Sinema joining them (Doug Jones will likely vote with Democrats, cause his philosophy seems to be 'to hell with the political consequences, I do what I think is right').
With the results of this being known already, I think the best is if there is a fast trial, so Bernie and Warren can go campaigning. Otherwise, the only winners of this might be Buttigieg and Biden (providing that he and his son are not called in the trial). And it is a very big advantage for them campaigning while Sanders is stuck in DC.