Taking the Night Train on December twenty-third Christmas train how does cold weather below freezing affect the train or the track's meaning does the cold weather affect whether the trip goes or not?

1) the website should answer your questions 2) not sure about the weather affecting the tracks but probably not. 3) you can definitely buy tickets at the station as long as there are seats available.

It gets cold, bundle up and check the weather. Never had the cold weather affect the tracks in the 10 years we have gone

Also was wondering can extra tickets be bought at the ticket office at the time of boarding? Thank you bought some tickets ahead of time in case train sold out but might need to buy more for relatives.