Wis. Stat. § 180.0727: Greater or lower quorum or greater voting requirements.

(1) The articles of incorporation may provide, or authorize the bylaws under s. 180.1021 to provide, for a greater or lower quorum requirement or a greater voting requirement for shareholders or voting groups of shareholders than is provided by this chapter.

(2) An amendment to the articles of incorporation that adds, changes or deletes a greater or lower quorum requirement or a greater voting requirement must meet the same quorum requirement and be adopted by the same vote and voting groups required to take action under the quorum and voting requirements then in effect.