Wow, the comments in this post are timely. I'm considering taking a month off to move to an unfamiliar, non-destination area to work on my creative project (songs) for 8+ hrs a day with no other commitments.
When I've done this in the past, I've really focused on maximizing and would generally work well over 8 hours a day. Usually 12, sometimes more. Exhaustion is its own creative juice. But not for a full month. :)
(sorry for offtopic)