I don't think the various Congress Critters get just how important it is to move really fast on this. At stake is not just the precedent or whether Trump gets to keep his Presidential pension, it's whether he pardons the guy who bludgeoned a cop to death last week in the Capitol, or the people who wandered the halls of Congress, destroying and looting offices, while talking about executing the Vice President. Trump could do that at any moment. Every second of delay risks another crime.
I mean, McConnell slammed through a lifetime appointment to the Supreme Court in 8 days to make sure she was installed before election day. If he wanted to he could do a Senate impeachment trial in a day or two. But he doesn't want to.
(Incidentally, there is no reason that Pelosi can't hold an impeachment vote now at the same time that she demands Pence remove Trump under the 25th Amendment. Impeachment does not need to wait for Pence to decide whether to act. We can do both and the two methods for removing a President have different effects on the outcome.)