We go every year at that time, for a 5-ish day trip. I'm a Halloween nut, so we definitely hit the HW parties. It's a great time to go, as long as they aren't opening a new Star Wars park or something. LOL.
Sometimes we stay on site, sometimes we don't. If you could luck into a great deal on a WDW resort, it might be fun to do, but there are plenty of options for hotels in that price range. $175/night will get you a GREAT hotel room with plenty of amenities. If we aren't staying on site, I set my target for $125-ish and usually end up with a Holiday Inn Suites, Spring Hill Suites, etc... I have lucked out and found Caribbean Beach, Saratoga Springs and Coronado Springs for RIDICULOUS rates and jumped on them. You never know.
Here's our last Columbus Day trip
Caribbean Beach (we tend to drive at night, so we left Wednesday afternoon and arrived after midnight)
Thursday - Pool, etc, then MNSSHP. As others stated, you can get in very early now. Typically we stay til the bitter end. This was the first year we didn't, but we still got in a good 8 hours at the park.
Friday - Crayola Experience, pool, etc. It's a shame to stay at a great resort and not use the facilities! It took us a couple years to really appreciate a day off from going to parks, so we do it now whether its a short trip or week long trip.
Saturday - Legoland (happened to be Brick or Treat). We have passes, our kids are 11,9 and 6 and love it. Plus, they just opened a new section. We stopped at a pin trading shop on the way to hotel.
Moved to Holiday Inn SeaWorld. Has free shuttle to park, so no parking, you get express passes, and there are 2 pools to use.
Sunday - SeaWorld. It was also their Halloween event.
Monday - Pool, Disney Springs for pin trading, shopping and food... then drive home. (we live in Georgia, not a long drive)