My understanding is that you want to save the hibernation file, then be able to reflash the RAM with that hibernation file.
This is not possible, and is technologically unfeasible. The contents of the RAM (and therefore the hibernation file) requires accurate knowledge of the system's current state. Over time the system is constantly changing, be it the OS's background maintenance or cache files being updated. Even if you don't do anything drastic such as run a software update, an older hibernation file would be inconsistent with the system's current state and you would encounter unpredictable errors; and most likely system crashes.