You can also find them in Wintergrasp. I've seen more Frost Lotus nodes there than anywhere else, although still not common. I think I've seen one outside of WG, and the rest came along with other herbs I picked.
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"the people can always be brought to the bidding of the leaders. That is easy. All you have to do is tell them they are being attacked and denounce the pacifists for lack of patriotism and exposing the country to danger. It works the same way in any country."
Hermann Goering, April 1946.