If at any time because of the removal of one or more credit union directors under this chapter, the board of directors of a credit union has less than a quorum of directors, all powers and functions vested in or exercisable by the board vest in and are exercisable by the director or directors remaining until such a time as there is a quorum on the board of directors. If all of the directors of a credit union are removed under this chapter, the director of the department of financial institutions shall appoint persons to serve temporarily as directors of the credit union until such a time as their respective successors take office.