One would have received more aids if a humanitarian disaster was either declared or widely perceived. In both cases, neither country officially declare disaster, however, the perceived human and assets loss was much more severe in the case of hurricane Katrina by foreign government and the people they represent.
For example, media giants such as CNN was broadcast damage caused by Katrina(wind and water) almost non-stop for more than a week, while speculated death toll was in thousands. The winter storm in China has hardly made major news outside CHina. Even when it made the news occasionally, people only see reasonably well dressed and well nutritioned seemingly healthy young men and wowen waiting for their train, and all those good-looking ice formed around trees and roof...Even people in Northern China were not aware of the severeness until days later.