FWIW: this isn't a universally-applicable statement, plenty of states forbid DWI during any and all operation of motor vehicles, including on private property.
Only a few states absolutely forbid operating a motor vehicle while intoxicated (I know Washington is one). That said, you’d have to do something pretty absurd to attract the attention of law enforcement if you’re staying on your own land.
That's just BS. If the cops show up for any reason and they think they can get a DUI out of it they will try and write one.