I wouldn't think of riding my Harley during the winter here in Scotland,it will go into dry storage,but not because of the cold, its the corrosive salt **** they spread on the roads over here I have seen what it can do in just one winter to your pride and joy.

But I could not go from November to March without riding so I have a cheap Honda (sold my Vespa !) which keeps me going during the winter.

The storage deal sound ok,it might be worth asking if you can have a look first and during the storage period and find out exactly how you would stand if the place burned down.