Old French city where champagne may be stored? (2,3)
I believe the answer is:
on ice
'where champagne may be stored?' is the definition.
'old french city' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'french city' becomes 'nice'.
'o'+'nice'='ON ICE'
(Other definitions for on ice that I've seen before include "one way to serve gin" , "Waiting" , "Predatory insect" , "Kept in readiness" , "In abeyance" .)