When I stayed at the Contemporary last year, I was able to turn my TV to a specific channel and hear the Wishes and the Hallo-Wishes firework music. Since I had a room with a theme park view, I just stood on my balcony with the TV up really loud and watched the fireworks with friends.
I don't know if any other monorail resort has this type of setup. I would have though the Poly would since you have a direct view of the fireworks. GF, maybe not as much.
Earlier this year I was able to be at the DVC lounge at Bay Lake Tower and they played the Happily Ever After music while the show was going on. We were all standing on the balcony/patio are watching the show.