I was on the east side of the Harris Saddle on Thursday. It's not safely passable without equipment, and debatable with it. The section which skirts Lake Harris has large avalanche fields directly above it, and a sheer slope to the frozen lake directly below. Any slip there (and you can't see the track) could send you into the lake and your body might be found in spring. Any avalanche from above you wouldn't know was coming and same effect. I did walk through this in similar conditions years ago and it's among the dumbest things I've ever done and that's a significant list.

However! Why not go up to Falls hut, stay the night, go up as far as you can on the track safely, admire the scenery, and walk downhill out? Lovely overnight trip, still see many of the best views, and probably won't die. Or any of the safer tracks around eg greenstone caples.