Zero will do just fine with the cold and can handle it for quite awhile.Kujo is an Akita to and when we lived in Florida I could never get him to stay out now that I'm back in Illinois and he's in the cold weather I can't keep him in.My experience with all of my Akita's has been that their much more tolerant to the cold then they are the heat.Once it would hit 85 degrees I couldn't get them to do much of anything other than drinking water and sleeping.They just hated the summers.Once it got cold they sprang back to life.I'd worry more about making sure he's comfortable temp wise when it 's hot .Akita's do very well in the cold,it's the heat that gives me the most trouble with them.In fact,Kujo has asthma and during the summer I have to give him meds at least every other day.I've only had to give it to him once since it's gotten cold.