Went with my bro and two nephews. We made a couple of smart last minute moves: Went to Target, bought two cheap sleeping bags and sets of long thermal underwear for each of us.
We laid one sleeping bag across our four seats and the other across our laps. It ended up making it kind of bearable but it was still this biting, cutting, deep cold. If I remember correctly it was like 17 degrees or so and "felt like" 8 degrees or something.