This would be great. This year they plan to offer passholders a discount, so hopefully you could just enter your passholder ID number and get the discount, or log into the passholder website and order (just MHO and a hopefull guest). Halloween night WILL sell out as it always does, usually within the first couple of months. Friday nights also sell out.
BTW: They have made great strides recently on their website. CMs can now book their discounted rooms through the online reservation center, so hopefully this is something that passholders will be able to do in the near future. My dream, to be able to log in with my passholder number and check availability at my own leisure instead of sitting on the phone. (Yes we are CM and AP holders, but sometimes we have to use the AP discount, when there are no CM discounted rooms available. This has been a great addition by making the CM discounted rooms available online and look forward to more online changes.)