As long as you remember your password, I'm pretty sure they'll still have your character on the server. The only thing you'll lose will be preset things like macros you've set. I was gone for like almost a year and then came back and Tevyn was still there, Quin. Twice.
It's probably because they don't have a huge influx of new people coming in and so there's more room or memory to keep characters on there? I guess in all seriousness, they
could get rid of your character if you were logged out for like 3 months if they needed the memory.