How many levels of flying can World of Warcraft learn in cold weather? How many grams?

My Lord, if you want to learn cold flight, the premise is that you need to spend 1000 gold coins at level 77. If you have a size 80, you can change it to a size 68 heirloom. If not, the landlord will still do the task until level 77! Studying in Dalaran! Come on, landlord!