The best place in world of warcraft to farm frostweave cloth as got to be Icecrown. You can stack it up so fast here and the mobs die like it's going out of fashion you can also pull big amounts at a time. You shouldn't really have any trouble killing here.
They also drop a lot of Runic Health Potion, Runic Mana Potion Uncommon items to disenchant or sell and vendor trash. The gold drop is good if i do say so myself. So head over to Icecrown and start farming your Frostweave Cloth here is the spot.
Or if your level 85 character wears cloth you might run into some little problems but nothing that a few cool downs can't sort out and god help you if your a healer many people think because your a healer you can stay alive more and it's easy for you.
My main is a healer and healing can be hard for us if the tank is a radish short of a salad show your healers some more respect its hard work healing you none stop.