I saved at chapters 5, 10, and 13. My ch. 5 save was at 3:30, ch. 10 at 6:12, and chapter 13 at 8:25. The best advice i could give you is to save earlier than you think you have to. Yeah you could be mr. cool and wait to save until later but you might as well save yourself potential frustration. Also I would only do one session at a time, cause you never know when you might get even slightly distracted and do something stupid. I died 3 times but luckily it was shortly after i saved every time. This made for one of the best gaming experiences i've ever had, it would probably be worth it even if you had to try dozens of times. The fear of death and losing hours of progress is exhilarating.