The Democrats will control the House and only the House at the federal level, so they have to make the most of it. There is lots of appetite among the base to investigate the administration, but people are going to want to see legislation too.
If I were Nancy Pelosi (and yes, I am operating under the assumption that she will be Speaker), I would call all the incoming committee chairs together and tell them to come up with one investigation they want to conduct AND one major bill they want to push, which if it has the effect of undoing a Trump action so much the better. These bills would not likely get through the Senate or be signed, but the point is to show Americans what Dems are capable of if given fuller control. The investigations would not need Senate cooperation, and there’s enough misfeasance, malfeasance, and nonfeasance in this administration that just about every committee would find jurisdiction over something. They would need a full court press to communicate all of this.
Maybe my fellow Kossacks can use the comments to suggest what investigations and bills could be pursued.