The last time I saw the OY at task was in mid-winter of 1977.
There was only about 3 feet of snow covering the tracks, but the base was fairly compacted.
487 was doing the honors, with a rider gon, boxcar-coach and caboose in tow.
As I recall, it took about 3 hours to get from the Chama yard limit to the narrows, and most everyone on board everyone seemed disappointed with the the slow progress of he consist.
With about 10 ft. of snow presently on the pass, I would be expect heavily compacted snow near the base. The rotaries were designed to be snowplows, not icebreakers, and the real question would how far up the hill a couple of K-36's could push the machine before the rotary or engines went on the ground.
Nothing against wanting to see one of the beasts under steam again, but I agree with Roger that a dozer is a much more suitable machine to clear the line.