Found the house
I had been trying to locate the house on Google Earth. The only clue I had is that it was along the Cane River. And from watching the movie, I could tell that you could drive straight in over what appeared to be a bridge. Or you could make a right out of the yard (as when Billy and Maureen go to the dance.) Also, there's a lot of space between the house and street. I found a location that fit this, although you can't tell for sure because you can't see the actual house from street view. Then I read something online that the house is at the end of Pratt's bridge, which is the bridge in the location I found.
2709 Louisiana 494, Natchitoches, LA. Enter that as an address in Google Earth to see.