I would bet against that. I've not personally driven 14 hours to a road game. But I have driven 1, 4, 4.5, 9, 9, 9.5, and 13 hours to get to road games in the past 5 years. And that's not an isolated occurrence.
I don't think it's at all a stretch to say BYU fans at a road games drive on average much further than those at home games. I'd speculate that 95% of fans at home games are within 3.5 hours of Provo (Idaho Falls ot St. George). If so, a sold out LES has maybe 2-3K fans that drive more than 3.5 hrs. For some of us, having a game within 4 hours is awesome. Every road game I've been to in the past 5 years has had anywhere from 6-18K BYU fans. And most of those fans have driven a lot more than 3.5 hours to get there (considering there's nothing within a couple of hours of Tallahassee, Oxford, South Bend, Charlottesville, etc).