Less crowded than on Main Street, but still spectacular viewing can be found near the Hall of Presidents,
or deep into Frontierland, past the Country Bears.
(But, from those locations you won't be able to see the new "show" that is actually projected on the front of the Castle,
"Celebrate the Magic," which begins 15 minutes before the fireworks.)
This a new version of this map that features a representation of the new hub and its FP+ Wishes viewing areas.
At this point, I'm not sure how the new "outer sidewalks" will be allowed or blocked
for fireworks viewers.
Not all of the sidewalks I've depicted have actually been built, yet.
As the actual Hub construction goes along, I'll revamp the shaded areas.