Hi Amanda! Thanks for bringing your question to planDisney.
Halloween is such a fun time to visit the parks. You're going to experience lots of festive décor, merchandise, and treats whether or not you're attending a special ticketed event. At the top of my list is the
Haunted Mansion holiday overlay. You'll want to check it out!
I understand being reluctant to choose a park that will be closing early for the day because of
Oogie Boogie Bash - A Disney Halloween Party. I'm from the Midwest too and coming all that way, you want a full day in the parks. The dates of the party have not yet been released. You can follow the
Disney Parks Blog for updates.
In order to enter the parks, you'll need a valid
admission ticket and a
theme park reservation. Those reservations open on a 120-day rolling window, and by the time you're in the window, I'd expect the party dates to be released, so you'll know which park to select. Also, so long as there is
availability, you can always cancel and rebook your reservation. If you're thinking about the
Park Hopper option, my tip would be to start your day in Disney California Adventure Park and then hop to Disneyland Park, which won't be affected by the Oogie Boogie Bash hours. That would give you more flexibility! You might even find Disney California Adventure Park a little less busy on a party day and be able to fit more in as a result.
I hope this helps! Have a spooky time.
Elizabeth