Hello! Transfer of envelopes is a bulk action which is done via a queuing methodology. As this is a SAAS product with shared server clusters, the transfer time depends on current requests and the size/complexity of the envelopes. Unfortunately, any time estimate I might provide would be offset by the issues above and would not be accurate. However, if I were submitting a job of that size, I would wait at least an hour for that to complete. You can always check the status by navigating to the Bulk Actions log under Settings in eSignature.
I hope this helps guide you and wish you an excellent day!
Jason Wiswell | Principal Product Trainer | Docusign, inc.