With a nod to the research of Steve Vladeck, a University of Texas School of Law professor, the coming vote on Jan. 6, 2021 is over-stated in one key respect. Under Sec. 1 of the 20th Amendment, the current Presidential term ends on Jan. 20, no matter what. If no President then is qualified to assume the position going forward on Jan. 20, then the Vice-President elect will serve in the office until a President is qualified. If neither the President elect or the Vice-President elect is qualified, then Congress shall pass a law which declares who shall act as President. See Sec. 1 and 3 of the 20th Amendment here.
3 U.S. Code Sec. 19 then provides that if neither the President or Vice-President qualify for the office of President, then the Speaker of the House shall serve in the office until a President or Vice-President does qualify for the position.
Some eleven senators have indicated they will object to the vote certification on Jan. 6. Some 140 House Republicans have indicated likewise. If they get their wish, that move may well lead to the Speaker of the House becoming President. The House Representatives and the Senators can engage in public theater as they wish. If their goal is to perpetuate Republican power, they will be disappointed. But, in any event, this latest drama is more political than legal.