Honestly, I have never had to reload mine. I fill the charcoal rings as full as I can get it, take 8-10 briquettes out of the middle and light them in a chimney and then put them in the depression where they once were. Then I assemble it and cook.
If you are using water, make sure you put boiling water in the pan. That way you don't burn fuel heating cold water. Also, it's really the wind that sucks the heat out of a WSM, especially in the winter, so fashion some sort of wind block to cut the wind.