A.A.
The only time we've taken a roadtrip since our little one arrived he was 6 months and slept. We drove overnight, it was about a 14 hour drive to get there. Hubby and I stayed up the night before, and my mom came and got DS when he woke up for the day. We crashed, and got up and left around 8, when the baby normally goes to bed. Coming home we didn't have the luxury of sleeping all day since we didn't have anyone to watch baby so we just took two days to get back and stopped whenever we needed to. Maybe look for kid friendly attractions on the way and plan frequent stops to let the little one run and get some energy out. Hopefully your 12 year old can provide some entertainment for baby, too! Good luck and safe travels!