FATMAP difficulty grade
Follow the Vallee Blanche to just before the Col du Gros Rognon then ski down left under the north face of the Gros Rognon, following weaknesses between the more crevassed sections.
Rejoin the classic Vallee Blanche under the Gros Rognon.
Warning: this is a very serious route in extremely crevassed terrain so make sure you are equipped, prepared and have practised crevasse rescue, however unlikely you think falling in a crevasse is- it is possible! A minimum would be each person to have harness, axe, crampons, an ice screw, 3 prussiks, several screwgates, a pulley/DMM Revolver karabiner, a couple of slings and 2 30m ropes in the group.
A more modern simple solution substituting for many of the above might be 2 Petzl RAD systems in the group.
If you have any doubts about this ski with an IFMGA Mountain Guide.