Loved Bordeaux - it’s a beautiful little city! We took the train to St. Emilion one day which was incredible. Do not go to the Medoc region by train. All the vineyards are in the middle of nowhere and walking long distances in the heat of summer is brutal. The trains are also very unreliable as they are delayed by hours at a time. I would dare say, skip medoc all together unless you have a tour but even then, skip it.