Since Germany relied on a flawed economic system, and was heavily in debt even before the war started, it likely would have collapsed. Or, turned into a stagnated state, such as North Korea.
Even if it had "won," there is no way Germany had the resources nor the manpower to hold much of the rest of the world. Or even Russia, let alone the United States.
Besides, all of these "what if" scenarios are pointless. What if France had won the Franco-Prussian war? The bottom line is that by '45 the US had the nuclear bomb. After that, Germany is finished.