They are stuck with him. She is the tie breaker and the democrats want those trillions in their pocket before the 2023 Congress is sworn in. She is on her way to get the new talking points.
Does not really matter. They don't absolutely need a tie-breaking vote, except to cover a few key allies who are pretending to be Republicans. In a pinch, they have enough dirt on those same Republicans that they can sacrifice a few of their "friends across the aisle" and win any vote they need.
Without Harris in the Senate.
The problem with Harris is that it appears she won't take directions from the oligarchs who are calling the shots. They cannot afford to install her in the Presidency unless she can be controlled.
I would bet that is what is in negotiations right now.
Biden is failing more quickly than planned. Harris has a lot of leverage for the moment.