Translation:In the evening the comrades are drunk.
While I like your idea about "tentmates", I've only ever heard "drunken" as an attributive adjective, never as a predicative adjective, in which cases I've often heard "drunk" instead. Imagine saying "you're drunken" vs. "you're drunk", or "you drunken fools" vs. "you drunk fools".
An example from the song "The Mary Ellen Carter" by Stan Rogers: "And the laughing, drunken rats who left her to a sorry grave // They won't be laughing in another day".
Actually, the more accepted forms, according to the Associated Press (AP) Stylebook, are "drunken sailor" and "the sailor is drunk":
"Drunk is the spelling of the adjective used after a form of the verb 'to be': He was drunk. Drunken is used before nouns: a drunken driver."
What the AP Stylebook is referring to, without using the jargon, is the difference between attributive adjectives and predicate adjectives.
I have a paperback version of the stylebook in question, and its full title is: The Associated Press Stylebook and Libel Manual.
It's a middle-of-the-road stylebook, not too stodgy, not too trendy.