(1) Whenever a vacancy occurs on a board of directors, including a vacancy resulting from an increase in the number of directors, it may be filled by the affirmative vote of a majority of the remaining directors, though less than a quorum of the board of directors, or by the shareholders, unless the articles of incorporation provide otherwise.
(2) Whenever the holders of shares of any voting group are entitled to elect a class of one or more directors by the provisions of the articles of incorporation, vacancies in such class may be filled by holders of shares of that voting group or by a majority of the directors then in office elected by such voting group or by a sole remaining director so elected. If no director elected by such voting group remains in office, unless the articles of incorporation provide otherwise, directors not elected by such voting group may fill vacancies as provided in subsection (1).
(3) A vacancy that may occur at a later date (under s. 607.0807(2) by reason of a resignation effective at a later date or upon the subsequent happening of an event) may be filled before the vacancy occurs, but the new director may not take office until the vacancy occurs.