Hmmm, that's a real tough one Paul!.
Just a couple of questions spring to mind.
Is the HV line system at the front of the property actually passing the front?, or is it a Spur that ends before your customers property?.
I'd go with the rear supply idea, if it were possible, but at the end of the day, it will be the PoCo that has the final say.
Rural supplies are never the easiest systems to design and even the simplest system can cost a bundle.
Another thing to consider, is the fact that the Spur line to the rear of the property may have been installed with only enough capacity for the single load on it, as strange as it seems, PoCo's do silly things like this, especially where profit is concerned. [Linked Image]