If you were to go on holiday what would you do with your forum? Would you close it for the time you're gone, hire someone else or something completely different? I would have Google run the board.
I would ask my Mom to log into my account and take my roll for however long I would be gone. Or tell an administrator that I won't be on and s/he will have to take care of x, x, x.
I have done this a couple times before, it has turned out alright one time. Another time I did that, I came back and my forum was completely dead. Which, Cmt Sports Forum had an unstable member and staff base then. I'd probably do it just like that again if I were to go on vacation again, I trust my staff to keep the forum going.
I just leave an away message on my forum about a week in advance and then go off on vacation. I don't have to worry at all, my staff are capable enough to run the forum in my absence. I was away from my forum for months without any note, when I came back it was still running as smoothly as before. So I have the utmost confidence in my staff.