The Desert is Cold in Winter
Luggage and bags: Going to Siwa in Dec/Jan. Take some warm clothes(really layer up). It gets cold at night. Our restaurant of the evening, the Kenooz Siwa is open air and it gets very fresh, particularly after an Australian summer
Anything more than the basic necessities
Miscellaneous: It's a village town and anything more than your basic daily necessities should be included in your packing list.