Brest-Litovsk 2.0 is ASB. The Soviet wont sign any treaty with Nazi Germany after Barbarossa. As Hitler had a track-record of using them as toilet paper.
The war was on to the death. Germany annexing everything to the Urals ASB. The Wehrmacht ruined itself getting to Leningrad & Moscow, they were screwed from day one. Germany's early succses shouldnt blind people to that fact.
That fact is highly disputable. Barbarossa was a close-run thing, or at least so claim such a classic author as Alan Clarke. I agree that the Germans were really just not strong enough in any number areas that mattered - logistics, production capacity, transport capacity etc, but nonetheless they came very, very close to breaking the USSR. Only slight changes are necessary for a capture of Leningrad and Moscow before the onset of winter. While this would not have ended the war, the damage to the USSR, especially from the fall of Moscow, would be monumental.
Under such circumstances I do not find a Brest-Litovsk 2.0 at all implausible (although I'd agree it's not the most likely outcome). Already in the summer of 1941 Stalin contemplated something like BLII. At that time, Hitler would never have accepted, but if offered after a costly winter campaign with no real end in sight to the war in the east, while the USA had just entered the war, who knows if Hitler had not changed his mind?