When you need a scene in a traditional narrowboat cabin, Coronis at London Canal Museum is ideal. Unlike cabins on floating boats, there is easy access to electricity and no problem if the weather is bad. The cabin is a reconstruction, although the hull of the boat is original. There is a traditional stove (not usable) and traditional roses and castles decorations.
The cargo hold, although not the original full length, could be used for a scene involving traditional canal boats where characters have to be filmed inside the hold.