There is no direct flight from Hangzhou to Xinyang, so you need to transfer. I think taking the train is more practical and cheaper. You can take k466/k467 16:50 to Xinyang and leave from Hangzhou Station at 03:26 the next day (you can get off work early in the afternoon on weekdays, which just increases your time at home).
If you want to go back to Hangzhou, you can take K468/K465 03:59 to Hangzhou Railway Station 14:20, or take K254/K25 1 20:33: 33 to Hangzhou South Railway Station 10:37 the next day.
Personal opinion, for reference only.