Request a 5th floor Epcot view. Requests are not guaranteed. Epcot view may also mean on a side of the resort where you can see the World Showcase but not Illuminations. I've stayed in 546 (1 bedroom) and it had a decent view. The connecting studio (544) should have also. 540 is a dedicated studio just down the hall.
You can only see the high fireworks; there's a reasonably long lull while the globe is out, but the music is audible.
I stayed in 422 (studio) View of fireworks was great, 420 (1 BR )
right next door should be just as good.
You can request those room numbers but there's no guarantee you'll get them.
425, 427 (studios) and 429 (1 BR) might also work.
I'm making a list of BCV and the comments regarding views. So a few more that peole have said were Illuminations views-422,459 ("good, not excellent"), 475, 544, 549 ("partial"), 550, 555, and 559.