In the US you will have lots of time to sleep due to waiting for an oncoming train to clear.
In most parts of the country we don't have dedicated passenger tracks. Amtrak (our passenger line) just rents track time on the freight lines. The problem is that freight lines are often single track lines so if there is oncoming freight you just wait until the freight clears. Sometimes this his hours.
Until we have dedicated passenger lines, long distance train travel is a non-starter here. It was too slow for my 75 year old uncle on a site seeing tour. His exact words were "fun, but never again"