227: You can't save during combat, and even if you somehow managed to acquire the worst weapons and end up trapped between two rooms of something murderous after deleting all your autosaves, you can still change the difficulty setting and make it through.
I don't mean to be rude, but I literally can't imagine this ever being a problem.
Maybe it won't be in Witcher 2, I don't know yet, but this is the most recent example I can think of: I played some of the campaign in Halo: Reach and was in a warthog clearing an outpost. The game did a scripted autosave while I was driving around letting the CPU fire he turret. Being as I'm not really used to the driving in Halo: Reach (and I'm guessing by extension all the Halo games), the autosave hit right as I was landing from a bounce next to and facing a cliff edge. The only checkpoint I could reload was that exact moment, leaving me to watch repeatedly as I, my warthog, and its two CPU passengers flew off the cliff and died as the Out of Area warning began its countdown.
For a more RPG-relevant example: playing Final Fantasy VII and VIII (not that it's exclusive to these two Final Fantasies or Final Fantasy games) and keeping a two save system. You go into a dungeon or area filled with baddies, you save at the beginning of the area and find a save point later on near the boss, get thoroughly trounced and eventually decide to get out and level grind elsewhere only to find you're locked in the area until the boss is dead.
In short, usually, if you need to go back further than your saves allow, it's at best only indirectly related to combat, and if it's not related to combat, it's because you want to go back and redo something completely differently, like exploring a different path in The Witcher 1.