Classic Christmas movie crammed in fantastic ideas of winter (3,1,9,4)

I believe the answer is:

its a wonderful life

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'classic christmas movie crammed' is the definition.
I know nothing about this answer so I can't tell whether this works.

'fantastic ideas of winter' is the wordplay.
I cannot really understand how this works, but
'fantastic' could be 'wonderful' (synonyms) and 'wonderful' is found in the answer.
This may be the basis of the clue (or it may be nonsense).

'in' is the link.

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I've seen this clue in The Times.

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