Can you provide a deeper explanation of what you mean by "restore" a voided envelope? Once an envelope is voided the document will be voided and has a VOID watermark. The envelope is considered unusable and isn't legal or enforceable. Per the DocuSign article https://support.docusign.com/en/guides/ndse-user-guide-void-documents:

"Note: You cannot unvoid an envelope. Once you void an envelope, or if a signer refuses to sign, which voids the envelope, there is no way to reactivate the transaction. Your only options are to create a copy of the voided envelope and start the transaction over again, or create a new envelope from scratch."