“Some of our tips are kind of crazy. A new panty hose. Drop an onion in there. Tie a knot.. Drop another onion in there. Tie a knot. So on and so on, then hang it up. So none of the onions are touching. And when you get ready for an onion you just cut the panty hose at each knot and the Onions stay separated. The moisture isn't touching.
Alternatively, If you take just a paper towel and wrap the onions individually and put them in the crisper in your refrigerator they will last you until probably around Thanksgiving.