Two authors have set out their visions of how Britain can work after a Brexit.
Richard North's "Flexcit" Plan, http://www.eureferendum.com/documents/flexcit.pdf .
Daniel. C. Pycock's plan - published via the Institute of Economic Affairs - http://www.iea.org.uk/sites/default/files/publications/files/Pycock%20BREXIT%20entry_web_0.pdf .
A number of Stayists have complained in the mass media that the onus is on the Leavists to set out a survival plan. The above two documents are the start of that process, so amount to a full answer to Stayists.