He can only take so much red wine (5)
I believe the answer is:
edwin
'he' is the definition.
(I've seen this before)
'much red wine' is the wordplay.
'much' indicates a hidden word (many of the letters in the clue).
'EDWIN' is hidden in the letters of 'red wine'.
'can only take so' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for edwin that I've seen before include "Dickens's Drood" , "and 19: Dickensian character" , "English king" , "Northumbrian king" , "-- Hubble (astronomer)" .)