Any public busses operating in mid Nov fr Chengdu to JZG and JZG to Huanglong? How often & how much?

There are buses from Chengdu Xinnanmen Bus Station or Chadianzi Bus Station running to Jiuzhaigou. The bus departs at 08:00 from Xinnanmen Bus Station and at 07:20, 08:00,08:40 and 16:00 from Chadianzi bus station. It costs about CNY64~90.
There seems only one bus at 10:00 from Jiuzhaigou to Huanglong now. It costs CNY43.

Thanks Fred for the info. Much appreciated. Btw do u know any nearby guesthouse at JZG or Songpan or Huanglong?

In Jiuzhaigou, there are many hostels. I think you could find one upon arrival.