Can the drunk's win condition be met even while he's still drunk?

Before they sober up, Drunks are not a specific role. (So a "Drunk Warlock" is not a thing).

Drunks are manually converted to another role by the game moderator when required to rebalance the game.

It would be unlikely for a drunk to still be drunk at the end of the game unless they died early, in which case they are not part of the winning faction.