The legislature, in order to insure continuity of state and local governmental operations in periods of emergency resulting from disasters caused by enemy attack, shall have the power and the immediate duty to provide for immediate and temporary succession to the powers and duties of public offices, of whatever nature and whether filled by election or appointment, the incumbents of which may become unavailable for carrying on the powers and duties of such offices, and to adopt such other measures as may be necessary and proper for insuring the continuity of governmental operations, including changes in quorum requirements in the legislature and the relocation of the seat of government. In the exercise of the powers hereby conferred, the legislature shall conform to the requirements of this constitution except to the extent that in the judgment of the legislature so to do would be impracticable or would admit of undue delay.