Just got back from going to MNSSHP -
TWICE - SOLO.
LOVED IT.
I ended up just wearing my Sunday football clothes for the second one.
If you have the means of creating a costume or even just a halloween shirt - I would wear it. You can pick up some Mickey Halloween ears inside the park if you want too.
The parade is awesome. Solo you can even catch the start of it from Frontierland, then when it ends - you can make it all the way back to city hall to see 1/2 of it again.
While the MNSSHP doesn't start until 7pm - your ticket is good for entry starting at 4pm -- SO you can make more valuable use of your day time if you like. A) Go to a different park until 3pm - then get your halloween stuff and head to the Magic Kingdom (since it's a seperate ticket anyway). B) Spend your day off site or at your hotel or doing something else -(ie pool, sleeping in etc.) - Then take your time getting to MK by 4pm. You'll be able to ride and do things with a full crowd until 7pm. Then they will make everyone without a wrist band leave - so you can still ride til 8pm - Parade at 8pm - then fireworks at 9pm. Rides til midnight.
THE BEST PART OF SOLO OR WITH FRIENDS FOR MNSSHP - since so many people bring kids - MOST OF THE RIDES ARE NO LINES AND NO WAITING** - especially after the fireworks end at 9:15. That's nearly 3 hours - I can testify that 3 hours of no lines will wear you out. (Although the candy will help with your energy)(Several rides I literally walked right onto the ride and didn't see ANYONE). With Space Mountain closed til Nov and some rides closed at night for MNSSHP - I'd bet a solo person focused enough could make it through everything open from 9pm-12am. **Sun-Thur nights (local kids will be able stay up later on the weekends)
I CAN'T WAIT TO GO ALL THE WAY BACK TO DISNEY JUST FOR 1 DAY FOR MNSSHP. Drive in that morning, check into hotel (well camping for me) - nap - then decent late lunch/dinner - then party from 4-12.
Tickets in advance are I think a $7 savings for adults.