Russian winter stopped Napoleon and Hitler, but that was not even in Siberia, both attacked the most populated regions of Russia. Conquering such a large land mass with a winter so extreme is not possible. So if it is any consolation to the Japanese, if they do migrate, they will be safe from invasion...but not frostbite.
He needs to refrain from vodka and public statements imo. Lol!!! I strangely find it funny to hear about his "offer" to the Japanese. Lol!!!! Hopefully some of the shell shocked Japanese got a much needed laugh out of the offer.