My wife and I will be in Paris for about a week and pondering whether going to Versailles with our 1 1/2 year old son would be worthwhile (we're going in Aug). I read in the forums that a stroller isn't allowed inside so that might be a problem. While he's only about 22 pounds, carrying him around shoulder to shoulder with other tourists doesn't sound too much fun.
We could perhaps rent a golf cart and drive around. I have read from some people that it was so busy during the July/Aug timeframe that it wasn't worth it.