Sad,if you want to break up now then break up now. Race and festival do not have any connection with the break up. If you give him few more days "happiness", do you think he will thank you after you saying break up with him ? It doesnt matter before or after.
kopfan, he can still receive lai see even he has a girlfriend :)
but true, tell him the truth if you dont love him so that he can spend time with his family. it wont make things any better if you just leave him after the new year.
Sad, are you concerned the festival atmosphere will drive the impact comes much bad if you break up in, it may happen in V. day or Xmans but probably not in Chinese New Year!!