Road trip with 3 kids ages 4,7,11 - what am I getting into?

Planning a 12-hour drive to visit grandparents in a month. We've done 6 hours before but this is next level. Any tested strategies? We have a van so space isn't the issue. Is it iPad the whole way or do people actually do the "games and snacks" thing?

Also - how many bathroom stops should I plan for lol