I've read that ocotpuses come out of their dens when it's time to go, which is backed up by our TONMO experiences. I don't know whether that's true in all cases, or just most of the time, but it's unlikely that your octo will die in her den.
It is with a heavy heart that I post today, I have needed to calm down... On Tuesday I found out that my well-meaning and excited customer was apparently anxious that the babies would have food over the weekend and decided to put several pieces of silversides and krill into the aquarium for the babies to nibble on (I guess with the idea that since that was what we had been feeding the parents maybe these tiny babies would eat it as well...) ?!?! I had thought we were all clear about what the babies were eating... Needless to say, with the flow turned so far down, the dead fish and shrimp quickly started to break down and caused an ammonia surge which killed everything. Hopefully this can be a learning experience and will not be repeated. FWIW I do feel that there was a very good chance at success in this endeavor.