I’m currently in Loches, ~20 km from Amboise. We’re actually visiting Amboise today. Here’s a few things to consider.
When do you need to return your car? We wanted to train to Tours, then rent our car. We leave on a Sunday and the rental office is closed. Because of that, we rented at CDG and drove directly to Loches. It’s more like 3 1/2 hours.
I slept well on the plane (Delta Comfort +). I’m used to driving in Atlanta and Paris was similar. Our car had GPS which was a necessity.
Check on Tours as a rental location. It’s a bigger transportation hub. Renting at CDG is a possibility only if you sleep on the plane and don’t suffer from jet lag (we stayed up to midnight the first night and were up at 7:00 the next morning and felt fine). Also, don’t do it if you are uncomfortable driving in big cities.
You’re going to love the region. Loches is a great place, off the beaten tourist path.