This author has a really interesting idea concerning the Iran nuclear deal that I hadn't considered:
By passing a resolution of disapproval of the agreement, even if they cannot override the promised presidential veto, the House and the Senate can signal their support for more robust opposition to an Iranian bomb than the current administration has mounted. They can supplement such a message with a resolution authorizing the use of military force in the event of further Iranian movement toward obtaining the bomb. Legislation of this kind would strengthen the hand of the next chief executive, whoever he or she turns out to be.
That's a very interesting notion that is worthy of consideration.
President Obama proved incapable of using the threat of Congressional opposition to a bad deal to get a better deal, and instead seemed to work with Iran against Congress to get this deal by elevating the role of the UN Security Council in approving the deal.
Perhaps all Congress can do is help the next president. If that's all they can do, they should do it.