It is not that the ESV’s use of “self-controlled” for σώφρων is incorrect. Rather, “prudent” better preserves the breadth of σώφρων, with self-control being one important manifestation of the virtue.
Balserak argues persuasively that Calvin repeatedly made false statements in order to deceive the French authorities, with the goal of protecting Calvinist ministers and churches in France.
Jesus’ central point thus was that to divorce your spouse so as to free yourself up to potentially marry another is not sufficient grounds for divorce.