Many Peruvians travel by bus with their babies. There are some excellent bus service operators (Cruz del Sur is a good one, very comfortable and secure). Renting a car is an option, but I think that it could be more secure by bus. Peru really isn’t too dangerous, but you need to keep an eye out for opportunist theft etc.

Stopping often in a car may increase the chances of theft etc. As far as I know, the Lima to Huancayo route is pretty good. You may be able to find a ‘colectivo’ taxi service, a shared taxi, from Lima to Huancayo. They are normally willing to stop quickly if you ask. A colectivo would also cut down on the time. The only drawback is if you get a driver who is in a hurry – they can be pretty hair raising.

All in all, I’d go with Cruz del Sur. And I don’t think traveling with your baby should pose too much of a problem (if you go by bus make sure you have everything you need for the baby in your hand luggage). Hope that helps a little!