Connecting service to new construction 1200 feet from the road.

We are building a new home behind our existing home where we presently have Xfinity service.  I have searched the website high and low to find a point of contact for where I should begin an inquiry about having a line run to the new house.  I called and spoke with a customer service representative and he stated that I would need to open an account and subscribe to a service to the new address before they could come and look, but after reviewing other posts, I don't think that is accurate. 

Any idea how I can start the process of getting a new line put in?  I am sure that they may need to be a plant extension to make that distance work, but my contractor is prepared to dig the ditch and lay the line.

Thanks.