Hi,
i was wondering how probable it would be to ascend to Vallee Blanche/Refuge Cosmique via the Mer de Glace glacier in one day, starting say around 9 a.m. from Montenvers station. Also, if that's too long of a trip for 1 day, is there any safe place up the Mer de Glace/Geant glaciers where one can bivy for a night?
Any suggestions/ideas are warmly welcomed!