I hope he gets to live in the general population.
It won't be too bad being in prison if you were a mere bank robber that didn't hurt anybody and did a five year stretch. But being in prison for murdering a child? That's the worst crime imaginable and most of his fellow lags would be after him. He's going to be fearing for his safety almost every moment for at least the next 42 years, should he survive.
Look at Ian Huntley. Huntley was sentenced to a minimum of 40 years for murdering two ten year old girls in Soham, Cambridgeshire, in 2002. During his time in prison he has had boiling water poured on him, had his face slashed and had an eye gouged out. He's still got another 20 or so years minimum yet to serve.
Whatever troubles and strives you may have in your life and least you can be rest assured that at least you aren't just a few days into a 42 year minimum prison sentence. It puts things into perspective. In July I will celebrate my 42nd birthday. So Cashman, aged 34, has to serve my lifetime at least behind bars.
As for the death penalty, I think Cashman's punishment is far worse. He could end up opting for suicide at some point, seeing it as a mercy.