The most common and most likely answer to this crossword clue is the 8 plus 7 letter word EBENEZER SCROOGE
I've seen this crossword clue in Financial Times
E
B
E
N
E
Z
E
R
S
C
R
O
O
G
E
More clues leading to the result EBENEZER SCROOGE
Buddy explains!
The straight part
We know that "with Christmas spirit?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case with christmas spirit? = ebenezer scrooge.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.