The Confederacy’s overall strategy required that, eventually, the North be willing to let the rebelling states go. Clearly, this didn’t happen, and I’m not proposing yet another “South wins the Civil War” scenario.
Instead, I’m assuming the war goes as historical. At what point should a rational Confederate conclude that surrender negotiations should be started? After all, the place occupied and slaves set free is better than the place occupied, slaves set free, crops and homes burned to the ground, and more men killed in battle for a cause that is lost on the battlefield?
And—if you settle early enough, perhaps you can negotiate something other than uncompensated emancipation?
The only rule is that you can’t start negotiations for surrender until the war is almost inevitably going to be lost…and others might well agree.
For that matter, would it make sense for any one state to start negotiations before the Confederacy collapses? And if so, what state, and what could that state gain by negotiating a separate peace?