I'd say it might be possible in a future expansion if we're lucky...I suspect Larian discovered that a highly reactive day-night cycle really needs to be designed into a cRPG from the ground up (taking into account housing for npcs, quest design, NPC scripting, etc)...
Agreed - though I really wanted to see this (and would still like to) the knock-on effects for NPC/environment design would be too great for a typical patch or expansion.
Still, if Larian have any plans for a "Developer's Cut" this would be one great addition to make.
