I’m amazed you would be able to develop it as a holiday business given it appears to be a residential area. Farms might get alternative use permission but that house - not so sure. You really would need to speak to a planning consultant. It’s not like you are converting barns!
It’s not really got many period features left! Is it Edwardian or later? It’s pretty ripped about inside and obviously needs modernisation. If pp for more houses was possible, one would have expected the vendors to do that first.
My view would be to build an eco house. Or a Huff haus. Something Kevin McCloud would like! I have an oak framed kitchen and I can see the attraction of an oak framed house. It might all depend on what’s in the area and how well a certain type of house would fit in.