Is it like a chest, where as soon as you enter the area, the quest is loaded up with a location, and thus not randomly generated when the quest is assigned? Or, is it determined randomly when the quest is actually given.

Example, I've got a quest where I have an idea where I want to actually go (because I like the location, and would rather have reason to go there), but the quest sends me all the way across the map in the opposite direction. Is it possible to reload before triggering the quest to get a different location? I've tried a couple of times, but the same location keeps coming up (where I know several other locations are possible).