Hello Michael and welcome back to the Disney Parks Moms Panel!
It certainly sounds like you've already done some amazing research for your planned August trip to Walt Disney World Resort and like you, I sure can't wait to experience the all new
Happily Ever After - Coming May 12th at the
Magic Kingdom Park.
On your behalf I've double checked the August schedule in exactly the same way as any Guest can for the
Fireworks Dessert Party with Plaza Garden Viewing and I can confirm that for me at that time there were indeed
available reservation times right up until the end of August.
I performed the same check for the
Fireworks Dessert Party at Tomorrowland Terrace and as you say currently reservations do not go beyond dates early May. This prompted me to call and speak with a knowledgable Cast Member to get some better intel and at this point all the information I can share is for you to keep checking back via
Disney.go.com for new future dates to be added.
It's always possible to speak with a Cast Member by dialling the
Dining Reservations telephone number contained within this
Walt Disney World Resort Phone Directory.
Wishing you happy and pixie dusted planning for your August visit to Walt Disney World Resort.
~ Jane