XmlDocument doc = new XmlDocument();
XmlNamespaceManager xsManager = new XmlNamespaceManager(doc.NameTable);
xsManager.AddNamespace("cds", "Cemat_DSI_Servizi");
doc.Load(path);
XmlNode node = doc.SelectSingleNode("//cds:Stato", xsManager);

string valore = node.InnerText;

 

Spero possa servire  a qualcun altro.