Does “well drunk” mean “to be drunk”?

This is some great commentary on understanding this verse:

The meaning is obvious enough, and there is no need to search in ancient wit for the original of a speech which is not too recondite to have been originated on this occasion. The best wine is appropriately given when the seneca are keenest, but when the climax of the festival has come, when they have drunk too deeply, or are intoxicated, then the weaker, poorer, and less fragrant wine is acceptable.

So yes, in John 2:10 where it states:

when men have well drunk

this is referring to being intoxicated. It is translated this way because of the word methyō used in the original Greek, translates in English to have well drunk or drink well.

In the context that this Greek word is being used it is appropriate to use this English translation instead of simply "drunken." This may be due to the lightheartedness of the verse.

As stated in the above commentary link:

it is a jocular statement of his own experience at feasts.