"Normal" is hard to say. Mine occasionally will whine a little, the same as yours when it is cold. After the car warms up it is silent. There is no doubt in my mind it is the throwout bearing unloaded, since it stops when the clutch is depressed. I would not worry about it, but keep and "ear" on it. If it gets worse then you will have no choice accept to do the clutch. Unfortunately, this repair is an all or nothing thing, you need to pull the trans, and once your in there, well it gets a complete clutch job. How many miles does the car have? Since the clutch will cost about $2K or so I would use the present one as long as possible.