Yes, it's a problem with octos and vacation. It's a problem with a reef tank, too, but you can ususally find someone who will stop in and see if everything is OK. These same people know nothing about octos.
If you remember, when Nepture was going away for a week, he had two sets of people coming in to take care of Ocho - one for the tank itself, and someone to visit Ocho every day! Ocho survived the vacation just fine.
Nancy