I've been making wine from just about any fruit I can get ahold of for decades, and when I bought the house 33 years ago, I planted 4 vines of DeChaunac, a French-American hybrid. At that time, such hybrids were thought to be the only ones that could tolerate humid summers along the east coast. Vinifera grapes were out of the question.
One by one, the vines succumbed, and from later research, it appeared to be Pierce's Disease - an unknown way back when. Well, one vine survived and is producing more fruit than any time since '83. Since this plant appears to be immune, I'm wondering if cuttings might be of value. Though I've been a judge as several Virginia wince competitions, I've yet to find a hybrid cultivar that is better than true vitus vinifera species.