the Nazis only chance of survival is...
...through a number of possibilities. Philip K. Dick pointed out with his novel-within-a-novel approach. Characters in The Man In The High Castle criticize the fictional novel A Grasshopper Lies Heavy for the simple fact that it posits a world wherein the Allies won WWII.
Rommel is said at one point in the book to be unbeatable more or less, while characters go on about how the Axis were destined to win for a variety of reasons.
In the characters' minds, the Axis's victory in WWII was assured by default, with notions of an alternate Allied victory being written off as implausible, or as its called on the alternate history forum "ASB"
And that's the approach I see far too often when people on this web site discuss an Axis victory. An Axis victory, even a fairly limited one, is written off as ASB. By this logic, the Allies victory is WWII was assured by default
But I don't think it was, just as much as I don't think a Union victory in the U.S. Civil War was assured by default.
For starters, the Nazis had many highly capable generals which were in some ways superior to opposing generals during WWII. Rommel was no doubt a great general whose abilities to win was hampered by a lack of support for his Suez Canal campaign.
Let's not forget Manstein, among others.
Add to that many other factors which to an extent went in favor of the Axis, and its not hard to see where and how they could have won at numerous points throughout WWII.
Obvious POD scenarios such as Stalingrad or Midway exist, as well as numerous smaller POD scenarios which could have ended in Axis victory, however great or limited that may be.
The Allies could've lost just as easily as the Axis in OTL, with numerous ways for them to lose which rival the Axis in scope.
Furthermore, history isn't set. the POD in Philip K. Dick's novel was FDR was successfully assassinated. After all, his premature death wasn't totally unavoidable.
And what about Winston Churchill nearly dying after being struck by a Taxi?
My point is that history could've diverged at many different points in time, such as Stalingrad or Dunkirk or the Nazi nuclear program (the latter example being the POD for the wonderful story entitled Moon Of Ice, which imagines an Axis victory through the nuking of the Soviets and of London)
What would a modern, socially and technologically speaking, Nazi Germany look like?
I'm not pretending to be an expert here, but I have several checked-out library books right now which clearly describe Nazi society from 1933-45 as well as detail minor and major Nazi documents from 1919-45
I'd like to add that Hitler's rise to power wasn't inevitable; somebody like Strasser could've risen to power no doubt. The Nazi Party wasn't destined to be the party of Hitler.
But being as the party was a racist and nationalistic party, it's manifesto openly and specifically discriminated against Jews. Strasser was just as racist as Hitler in views as the documents show from the early years of the party.
As such National Socialism was primarily a middle-class, shopkeepers movement (a form of 'shopkeepers' socialism') which had considerable backing from wealthy industrialists despite the party's rhetoric about supposedly being anti-capitalist and so forth. (leading industrialists actively financed the Nazi Party's 1932-33 election campaign, with the Circle of Friends of the Econom
y coming to the fore after the Nazi Party's seizure of power)
Assuming that Nazi Germany continued to exist post-1945 I'd imagine that the SS would grow considerably in power and prestige, esp. assuming if the planned state of Burgundy was carved out of occupied France after an Axis victory in WWII.
In the excellent AH TL The Anglo-American Nazi War, the SS soon enough replaces the Wehrmacht as Germany's sole army which is a real possibility IMHO assuming Nazi Germany survives.
Nazi Germany would of course be highly authoritarian as well as heavily bureaucratized (as the National Socialist movement was far from being anti-bureaucratic), with large doses of nationalistic and racist propaganda being spoon-fed to Germany's citizenry.
Colonization by 'Aryans' or (supposedly) ethically-pure Germans would take place across Nazi-dominated Russia, esp. in the breadbasket of the Ukraine. Leningrad would be destroyed, being as it was to be completely wiped off the face of the earth.
Poland was designed in OTL post-war to be kept artificially low as far as culture, education, living standards go for native Poles. I'm sure that gradually the native Poles would be replaced by Germans if the weren't already being replaced across occupied Poland.
In shorter words, a surviving (if not thriving) post-1945 Nazi Germany would be wholly Orwellian. It was and would continue to be a police state dominated by an aging, cult-like Hitler, whose death could very well lead to a power struggle inside the Nazi Party.
Just Thank goodness the Nazis didn't win WWII.