In reply to my own post.

1 Shelter-metal avalanche shovel (each person due to avalance hazard
and quickness of shelter building ideally) with the ice axes
they can build a roomy enough snow cave to keep away from the wall
of the shelter and vent it well. Much warmer than a tent. Metal chops through hard snow better than plastic. 1.5 lbs each

2 Water- stove, white gas with a quart of fuel or so as they will need lots of water to stave off hypothermia and frost bite for the several days trapped. They will need to be very careful to ventilate properly, but it has been done safely countless time on climbs. MSR Whisperlight is a good one.
3 lbs with fuel and pot. One or two per group.

3 Food- high calorie, like plastic jar of peanut butter etc.. 2 lbs each
(more is better)

4 PLB. Not listed earlier in this list 'cause so far it wouldn't have saved their lives (at least the one up high in the cave) 'cause rescuers can't get there yet.
(A gps and cell phone may be more valuable for both self rescue and
helping searchers, but that adds another item).

5 sleeping bag, synthetic fill 30 degree plenty when combined with the
snow cave and clothes. They can sit on their ropes and packs for ground insulation. Preferably each person, 2 lbs each.