Quick update to the original post.
I have managed to get hold of the warden though the site doesnt open for another week, and although its at the wardens discretion, this particular one is OK with the plan. The only proviso is that if we are away for more than 48 hours, we have to disconnect the electric and shut the gas off, which we would have done anyway. The club insurance have added a note to my file saying that we have informed them too and they are also happy.
For you guys that said they wouldnt bother informing the warden, they only charge for the unit and one person rather than two for the time you are away, which is obviously a money saver 🙂
Alls well that ends well. It pays to be upfront and honest.