Kunming railway stations to Chengdu railway station

May i know

1) Is the train from KM go to Chengdu during December winter ?

2) Is the railway from KM to Chengdu open during December winter ?

3) Can i book through internet booking for the train ticket from KM to Chengdu more early within 1 month?

Since i am having a long holiday in Lijiang n Shangri-La n cannot make it to arrive KM more early to book for the ticket.

4) Can i do the internet booking for the train ticket since i am not a China citizen because i am a Malaysian
( Foreigner )?

5) what is the train ticket booking web address in China ?

6) How can i do the booking ? any idea ?hope to get your help.