Pinot? That could be the last straw! (8,5)
I believe the answer is:
breaking point
'last straw' is the definition.
(I've seen this in another clue)
'pinot? that could be' is the wordplay.
I cannot really understand how this works, but
'be' could be 'point' (pointing is a kind of being) and 'point' is present in the answer.
The remaining letters 'breaking' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'the' acts as a link.
Can you help me to learn more?
(Other definitions for breaking point that I've seen before include "Critical moment for collapse" , "Moment at which something gives way" , "The end of one's tether?" .)