It's too late for OP, but I guess for anyone in Seoul for future countdowns, the Lotte World Tower has had NY fireworks for the last (at least) couple of years.
I watched the 2016/2017 one on youtube and it was spectacular.
So I braved the cold for the 2017/2018 one last week but it was disappointing as heck. I should have just stayed home and watched the livestream on youtube (the lotte world tower youtube acct broadcasted the fireworks live).