The problem with the idea of "optimum conditions" is that it doesn't exist in the wild. In the wild half the snakes can die during brumation, so brumation does beat the crap out of the snakes in the wild, too.

Not much of this has anything to do with what happens to our snakes in captivity. We can, at least in principle, control the humidity and the temperature, draft, access to water, we can influence the parasite load, the diet and to some extent the general health of the snake (we can't do anything about the genes, though), just to name a few of the factors that are bound to influence the snakes' chances of survival. Still, there are always things we could do better.