This does spund like a do-able idea and the pic of the converted van posted looks pretty great for the type of description you have given us however as a last tip I would advise you to contact the ferry company you are going to be travelling with and describe this to them. I'm saying this...
I am definately a city girl, I long to be in a peaceful country house somewhere beautiful one day when I am married and settled down with my children but not yet! At the moment I have too many strings in the city so..definately a city girl!