It never fails to surprise when my parents-in-law, two very intelligent people, will happily drink a glass of wine and then drive home. Maybe it’s a generational thing as none of my friends my age would dream of taking the risk. I would assume (hope!) that they are still under the legal limit after one glass but I can’t help but think their driving might be slightly impaired. They live 2 hours from us and, now it’s winter, will be driving in the dark so I would think they would need to be extra vigilant.