It would have been almost impossible for the South to have been successful. They had one major and a few minor export commodities. Cotton the major, tobacco and sugar the next largest. Their major cotton customer was the Brits who were rapidly developing their own cotton sources in Egypt and other places. Tobacco, as you can see from the worlds sugar and tobacco in these days are readily availaable from a lot of sources. The South had manufacturing manufacturing capability or capacity. so they still would have to buy most of their railroad and other heavy machinery and iron and steel products from others for some time until the Alabama mills came on line and they would have to buy the initial machinery from others.
They had some leaders who desired to expand Southern style slavery based plantations into other areas. Not all but some. Unfortunately there were people there who would not have wanted that, and succinctly they would have run into the Royal Navy, and the spanish Navy and Army. (Assuming the US forces weren't also involved) Now if you think the South could have gone up against the Brits and the Spanish when they couldn't build their own ships or small arms or almost anything else?
No the South would not have made it. They would have remained dependent on the North and Europe for a long time.