Siobhan,
I have had all the application forms through from the AOR and did wonder who booked these things quite that early!
I went last year as a student and it was incredibly useful and interesting. I booked a week before! I didn't stay over as it was only an hour away from home for me but I think that accommodation may have been a challenge that late in the day...
It is definitely worth it, but I won't be sending any deposit cheques quite yet .