Maybe Trump should strike a deal: (i) permit Kavanaugh to be confirmed, and (ii) allow RBG to resign, in which case Trump will nominate Garland as her replacement.
Garland is not a Federalist Society type, but neither is he RBG. He's actually a fairly moderate jurist who is perfectly qualified for the Court if one takes off one's ideological goggles for a moment. As much as the right was apoplectic at its lion Scalia being replaced by a liberal, so would the left be (with equivalent justification) apoplectic at RBG being replaced by a Federalist Society type.
I know that compromise for the good of comity is not in the vocabulary of most here, but in reality a Court with both Kavanaugh and Garland on it (and no RBG!) would be a distinct improvement.