If the south had won a long and protracted war I speculate that the reparations required of the U.S by the Confederacy would have ruined them financially and that the most, if not all, of the former union states would have eventually either reunited with the confederacy or joined the Canadian union. They could not have survived as they then existed.
I highly doubt that. Reparations didn't cripple France after the Franco-German war. And whether you want to admit it or not, a defeated Union would still be an enormous economic power when compared with the Confederacy. It had over 4 times the free population as the South, 10 times the manufacturing, 14 times the textile production, 38 times the coal production and 15 times the iron production. The U.S. had 3 times the farm acreage, 7 times the railroad mileage, 9 times the merchant ship tonnage. It produced more livestock, more grain, more in almost every area except cotton. The U.S. would have continued to grow and outstrip the South in every area so long as it was dependent on cotton production. The U.S. future was far brighter than the Confederacy's was.