It can't be answered truly by anyone not facing real time, true, all we can do is speculate on what we would do. Here's some words of wisdom from Mike Tyson:

'The hole was a trip. They threw me in a six-foot-by-nine-foot room with just a mattress on the floor and a toilet. During the day they would remove the mattress and make me sleep on the concrete floor because they didn't want me to be comfortable. It was pretty inhumane to be in a room 23 hours a day with the light always on, but you get used to it. You become your own best company. In a weird way, you get your freedom in the hole!'

I personally can relate to that statement. During my years of incarceration, in some ways I felt more free in there than out here. But not everyone's story or outlook is the same. You might feel the complete opposite.