Fitting a washer through a 23" opening
I measured a Stabler at our warehouse and it is 26 1/2 " deep and 27" wide.
I also measured a SQ TL washer and it will come down the stairs if you remove the cabinet, cabinet top and bend the cabinet slightly. You also may have to remove the washer assembly from the base-plate, then it will go down through a 22" opening. It is easier to do this with a WP DD washer, but it is possible if you or your delivery people are also service technicians.