Regardless of whether or not Jefferson Davis might have offered a surrender, I suspect that the only terms Lincoln would have accepted is immediate dissolution of the CSA and readmission of each state individually to the USA on terms established by the federal government. Also Lincoln would have been under considerable pressure from the radical wing of his party to disenfranchise anyone in the south who had initiated or voted for secession, been elected to office in the CSA congress, or served in a high rank in the CS military. Then there would be the continuing issue of slavery to addess. I suspect it is a non starter.
I agree with you. Lincoln's terms would be like they were IOTL - the states would be readmitted into the Union. The slaves - legally freed by the Emancipation Procalamation - would need to be recognized as emancipated. There is also the possibility that certain laws respecting the rights of black citizens, or perhaps even land reform to provide liberated slaves with their 40 acres and a mule, be enacted before the southern state would no longer be considered in rebellion.
However, the Confederates could ask for a variety of things.
1 - Compensation paid for loss of property (slaves and possibly land).
2 - Amnesty for everyone who rebelled.
3 - No reconstruction and quickly allowing states to resend representatives to Congress
4 - Agreement that various laws passed by Congress during the South's absence would be repealed or replaced by new laws upon the return of Southern lawmakers. I am thinking of things like the tariff increases enacted after the South left.
That combined with less destruction of property resulting from Sherman's Marches, and far less dead would be a great benefit to the southern states.
Unfortunately, we all know that the leaders of the Confederacy were not enlightened enough to do so. If they were, they would never have seceded to begin.