What will have happened to the slaves freed under the Emancipation Proclamation? Between the enactment of a cease-fire and the signing of a peace treaty, I would imagine that there would be a flood of frantic slaves attempting to escape into the Union lines before the Union armies withdraw.
Oh yes. I haven't gotten to the Union side yet but it is safe to say many thousands of escaped slaves are going north. The EP will be revoked but the FSL will be very weakly enforced and not at all if the slaves come from CSA states. Also all colored troops and their families will be free as Pendelton is fully aware the colored troops would revolt if that didn't happen.
In the short run Tennessee will more of a slave state then ever due to geography and economics. It is surrounded by slave states and will be the only Union state that is so. Southerners are very poor at the end of this war and slave owners and TN can easily outbid them. It would be even higher but some of the slave owners are smart enough to worry about what would happen if the Republicans got back into power. If that happens it will be difficult to stop abolition in some form or other.
Maryland and Delaware slave owners will try to sell their slaves south before they all run away. KY and Missouri will last somewhat longer but they will have problems with escaped slaves as well, particularly Missouri as it almost surrounded by free states.