Fly vs Drive with 1&3 Year Old

Planning a family trip with our 1 & 3 year old and deciding whether to fly vs drive. Any opinions? The getting there doesn’t sound fun but the being there does. More details:

-2 parents, kids ages 1&3 -Car ride is about 16 hours without stops -Flying about 5-6 hours and no direct flights -Need a car at destination so would need a rental if fly -Would need to travel with car seats. Do not need to travel with a stroller or portable crib. -OK with driving during nighttime -Unlikely to fly during nighttime -We have the option to stop somewhere for a day on the way to breakup the trip

What would you do? Drive or fly?