Hard to say. I'm not a historian, so I can only speculate. I would assume that Hitler would eventually select a successor and there is no way of telling how good that person would be at keeping the Reich in order.
comparable to say Soviet communism’s collapse in the real world
As far as I understand it, the fall of the Soviet Union was preceded by at least a decade of economic struggle that was caused by a multitude of factors. Basically the only thing they had to export was oil and weapons and the only nations they could trade with were relatively poor. When their oil production cost kept rising, they just couldn't keep their exports high enough to import enough food and luxury goods to keep their population happy. This was a prime driver for unrest in regions that bordered the west, especially East Germany who of course got news of what life in West Germany was like. The Soviets were eventually forced to open the Berlin Wall and from there, there was nothing they could do to keep people from just leaving and fully collapsing the economy in the process. To this day, 35 years after the reunion, former East Germany is way behind the rest of the country even though on paper they have the same chances as everyone else, just because there has been a massive brain drain.
So overall, the collapse of the Soviet Union was less a failure of communism itself and more a failure to counteract their economic weaknesses as well as a result of their isolationism. The USA didn't win the Cold War because of the inherent superiority of capitalism but because the world drinks Coca Cola, wears jeans, watches Hollywood movies and works with IBM-compatible PCs. If the Soviet Union had pivoted their economy to those kinds of goods and had managed to export them to the west, they might have become what China is today.
So it all comes down to the question if alternate-history Germany manages to do that. With technology advancing slower overall and therefore becoming less of a factor in global markets, and at the same time keeping a lot of top scientists who in the real world left for the other superpowers, they could probably do it.
There are several events that might have had the possibility to turn the war: