Sourdough never lasts very long in my house, maximum 3 days, usually 2! To keep it fresh though, I wrap my loaves in strong plastic bags, expelling as much air as possible and tying then tightly. (I reuse the same bags over and over..!) And I store it like that in my bread bin.
*Only ever store or freeze fresh loaves once they’ve fully cooled.
When I bake several loaves at once, I freeze the extras. Again I wrap them in plastic bags and put them in the freezer.
To defrost I remove the bread from the freezer and the bag, sit in on a cooling rack, and let it defrost at its own pace for several hours.
The loaves defrost perfectly, usually maintaining their crisp crusts. You can however re crisp or refresh a loaf in a warm oven, around 180C, for 5 minutes if you wish. Sometimes sprinkling the loaf with water aids the crispiness.