Hoop Dee Doo is a wonderful night out for two adults. The food is excellent, and the entertainment is super fun. Well worth the money, even at Disney pricing.
The Halloween Party is also fantastically fun. My husband and I have gone 4 times in 2 years, never with kids, and had a blast. It is equally a great time to Hoop Dee Doo and well worth the money, too.
That said, you would be doing a big injustice to both excellent events by combining them both into the same night. Either schedule both but on different nights, or pick which one appeals most to you and take a pass on the other.
If you pick the Halloween Party, what about adding on the Hallowishes Dessert Party? Not only will that get you reserved parade viewing at the flag pole in Town Square and a special spot to watch the fireworks from Tomorrowland Terrace, but you also get a wonderful dessert buffet (which also includes fresh fruits, cheeses, crackers, and beverages) which would more than round out a quick service meal in the park.
If you go with Hoop Dee Doo, add on a private carriage ride (currently $45...and that price is per carriage, not per person). Your horse and driver will take you through the campgrounds to see all the Halloween decorations on display throughout the Fort. It definitely has a romantic feel for a honeymoon trip. Or, for $8 each, you could go on a wagon ride (not private....other guests will also be on board the wagon). You could easily round out a full night at Fort Wilderness with the dinner show, a carriage or wagon ride, and even the Electric Light Parade or Chip & Dale's campfire sing-along if you plan your timing right.