There is not much snow in downtown area, but if you go to mountain areas like Jiuzhaigou, HUanglong or Xiling Snow Mountain, you'll see snow. You can see pandas there in winter, winter is a better season to see pandas than in summer. Here are some Chengdu Tours(https://www.travelchinaguide.com/package/chengdu.htm) for your reference to visit these places one by one~