This line of inquiry is rather neurotic and presumes that because this President rejects Congress' self-declared (and unconstitutional) assertion of a power to "oversee" the President's execution of the powers of his office, that he is acting as a dictator (or something). I have many times in this forum asked for the words in the Constitution that codify this bizarre right, to no avail. The three branches of the Federal Government are co-equal, and Congress has no such right.
To those who maintain the Imperial Presidency fiction I point out the following. This President has been abused violently by leftist Jurists in the various Federal District Courts (mainly on the Left coast), who issue orders that purport to bind the entire Executive Branch throughout the entire country, based on utterly specious readings of law and the Constitution. In every single case where these rulings have made it to the USSC, they have been shot down, utterly. And yet this President/Dictator can do NOTHING ABOUT IT, other than complain to Congress, which ironically has the power to curtail the jurisdiction and power of the Federal courts, but declines to do so.
Eventually, my position will be vindicated. Congress has no general power to "oversee" the President or his activities. OTOH, there is an implicit power to query the Executive Departments on their implementation of laws. For example, if Congress were to pass a law ratcheting up the CAFE standards, they could drag in the Administrator of the EPA and demand to know how this goal will be achieved. But this is NOT demanding to know about conversations, policy discussions, etc., within the President's inner circle. These are none of Congress' business.
Sadly, the probable final outcome is that when the dust on this impeachment settles, the President will be "cleared," but that essential question will not be challenged/resolved in court, as it should be. The fact is that the Democrats DON'T WANT IT TO GO TO COURT, because as it stands now, they can continue to claim that this President has "obstructed" Congress.