A problem with Nazi Germany v. America Cold Wars is that unlike Communism Nazism isn't an ideology that can gain support from everyone regardless of what continent they reside in as it is a racial ideology to the core. All such a Cold War would consist of is the Nazis and Italians engaging in brutality to get the colonies of Vichy France, Spain, Portugal, Italy etc. in Africa and eventually running out of money before collapsing in the 60s or 70s. Not to mention the Slavic insurgency in Eastern Europe. It wouldn't be the worldwide global struggle as the OTL Cold War was.