In the past Martham Boats has allowed folk to stay on their boats whilst in the shed. Re BSS & Insurance, not sure whether you need to be covered whilst towing her across country but effectively, as far as the Broads is concerned, you won't need either, nor a toll, until you launch. Personally I'd phone Broads boatyards such as Martham Boats or LBBY and explain your dilemma.