They could have won had Lincoln been as sane as "Mad King George". Nobody expected the North to expend such blood and treasure to subjugate them.
No, they would not have won at all. The bottom line is that if Lincoln, or McClellan (who opposed him in the 1864 election) had not continued the war, the business interests in the North would have found somebody pliable enough to continue the war. Have to say that i'm very surprised that your cynicism concerning Northern monied interests didn't let you see that.
After all, it was not as if they or the Southern aristocracy were doing the actual fighting and dying (with very few exceptions on both sides). The war was going to continue to a conclusion no matter who was in the White House or the Gray House in Richmond.
Rich man's war, poor man's fight. Same as it ever was