You cannot book (or should not be able to) book ADRs for January 9 2018 as it is more than 180 days out. You CAN book your resort, just not online. Typically Disney posts the new pricing in June so it would be before the 180 mark.
Would it be better to post the pricing out the 500 days and anything beyond 180 days add the disclaimer that Prices are subject to change until the 180 day mark? Do you think that would cause a bit of an up-roar?