Maybe not, but last time I looked obstruction of justice/abuse of power/perjury/extortion/ illegal payoffs/conspiracy/money laundering/etc. were still grounds for impeachment or criminal acts. Of course like "collusion" this is only a "possible" scenario.
Nixon was impeached on three counts: obstruction of justice, abuse of power, and contempt of Congress.
Clinton was impeached on two counts: perjury and obstruction of justice.
My bet is that Trump should be good for at least 4 or 5.