g-love sent me a 64 oz growler from PA. He centered it in the box, added peanuts up the ass, wrapped it in probably an entire roll of the big sized bubble wrap (okay not that much), wrapped packing tape around the top which already had plastic around it. Then every other bottle was pretty much wrapped with the same care. It was an epic packing job that literally took me about 20 minutes to get through. The biggest thing was padding and putting it upright. I do not think he wrapped it in a trash bag. My memory fails me but I would do that. It's a lot of liquid to leak should something happen. I also recall the growler having the same space on the bottom, sides, and top with lots of padding.
As for keeping cold, I would just hope there was headspace in the growler.
As for keeping cold, I would just hope there was headspace in the growler.