Welcome to planDisney Michael!
How fun that you plan to dance and party the night away at the
Atlantic Dance Hall! It sounds like so much fun. Remember that this is a 21 and older venue, so the little Mouseketeers will need to have other plans.
Since buses only run for about 60-90 minutes past park closing time, you will be unable to catch a bus at that hour. I suggest calling for a taxi or Uber/Lyft to get you safely back to Disney's Contemporary Resort. If you end up heading home early, you can try catching a bus from one of the nearby hotels to the Magic Kingdom then walk back to your resort.
Before heading to the Atlantic Dance Hall, you might want to enjoy a delicious dinner at one of the restaurants on the Boardwalk. I am a big fan of
Trattoria al Forno. Their chicken parmesan is out of this world!
Dining Reservations are recommended.
Have fun at the Atlantic Dance Hall! Hopefully you plan to sleep in the next day and lounge at the pool. Enjoy!
Cathy