Wow that's a lot! Though my commute to work, which is about 3.5 hours total day, and my hour long gym sessions 4x per week, would probably help me crush those audio books in a month. So far I've listened to the first 3 Harry Potter books in less than 2 weeks. I think I'll be done with all 7 by mid May, maybe earlier.

Game of Thrones is on my list. I'm thinking of listening to the LotRs series and The Hobbit as well, though I feel they'd take me a bit longer because Tolkien gets overly descriptive and it can get a bit dry in some parts.

Good luck with the listening! :D