I went to an estate sale this weekend and she had styrafoam coolers that she used for storing her fabric and art supplies in, looked like a great idea to me. I don't know where she got them from but they were square the walls were about 1 1/2 inches thick and they were light. Sounds like a win win in your type of situation. I store my stuff in a heated storage unit and have had no problems, the heat keeps it at around 55 in the winter and regular in the summer. Different places have different problems. I have some in plastic bags and some in plastic totes in this storage unit and have had no problems what so ever. Heat can cause fabric to rot as well as dampness.