I see it as two secession movements. The secession of the deep south states was opposed by most thinking Southerners, including Robert E. Lee. Relatively few argued against the RIGHT of secession, but many felt that circumstances did not warrant such drastic action. Indeed, South Carolina seceded before Lincoln even took office. The deep south states had not yet exhausted all their legislative and judicial recourses to preserve slavery, in which they had had a fair amount of success in the preceding years. Their bull-headedness resulted in a tragic miscalculation and they lost everything they had. It took a century to finally climb out of the hole they had dug for themselves.
The secession of the upper south states was, I believe, a more principled decision. They seceded, not to preserve slavery and the wealth that institution provided, but to oppose the use of Federal power to coerce their sister states. When principle is involved, self-interest takes a back seat. It was with great reluctance that the great men of the upper south chose to take their states out of the Union. Unlike the calculating, manipulative moneyed class of the deep south states, who had alternatives to secession, the upper south states were left with only two options, principle or surrender of their beliefs. In that regard, it's hard to say that the secession of the upper south states was a "mistake" they could have avoided.
Just my humble opinion.