Road Trip to Bangalore with Infant

Hey everyone planning on a road trip with a 5 month old from cochin to Bangalore using a car rented from IndusGo in the Month of April or May. We wanted to travel to cochin>Munnar>Kodaikanal>coimbatore(Ad Yogi)>Ooty>Bangalore. One to two night stay in each location explore and move on. IndusGo offers a oneway trip between major cities… any other suggestions would be of great help. Wanted to know about the circuit, any challenges which I should know of before planning the ride? Shall I take up train route(got plenty of time so can book train tickets soon) to be less concerned about driving exhaustion and safety of my family on the ghats? Any other suggestions on the trip or any small destinations that can be covered on the way which are a small detours.