Unfortunately, this is another case of playing into their game for political points.
The correct response is to simply point out that such a settlement doesn't have force of law and ignore it as a joke. Trump screwed up again, not understanding how any of this works, so he lost.
By reacting like this, those House Democrats legitimize it and join Trump's folks in the low ground.
But they do get attention from it, no matter how self-defeating it is.