alright, I'll give it an honest go.
You are gonna have to accept some caveats to at least flirt with plausability.
First is either completely removing hitler, or sufficiently change him to have him be nothing like OTL. That being done you have someone much more smart running things, this alone doubles the Nazi's chance of succeeding, although doubling one in a million is still just two in a million so there are limits.
You also need to go back pretty much to the very beginning in 1936 when the nazi's took power, or preferably get them to take power earlier to give them more time.
The Nazi party would have to be more well run with the main players competing less and cooperating more, which is possible with a smarter fuhrer.
Tone down the antisemitism to the point that the NAzi's aren't shooting themselves in the foot, maybe just deport the jews in stead of exterminating them.
Eliminate or change enigma and beef up abwehr and maybe the allies don't get to read the Nazi's mail before they do.
It is my opinion that the A-Bomb being invented when it was OTL was highly unlikely, and happened largely because the allies thought (wrongly) that there was a serious threat of Nazi nukes. Without the unique set of circumstances of OTL the first A-bomb might not be blown up until the late fifties or even as late as the sixties or seventies.
You can keep the US isolationist by having FDR not get elected or lose reelection after his first term, maybe even have the great depression be worse for the US, and cause some major internal strife which keeps the US out of the war. Also no FDR in office could mean that there are no embargoe's against Japan, and thus no reason for pearl harbor. Given enough time and without the US kicking their ass, the Japanese may just be able to conquer china, maybe, and also the Russians have to stop supporting the Chinese too, and maybe you get a Japanese controlled China.
The Russians could be severely weakened by having worse purges, combine that with somehow more success in the winter war(perhaps having it happen in the summer in stead) and the Red army may not learn its lessons in time to fight the Germans, also it might scare the poles enough to throw their lot in with Germany.
You could also have the western allies be lilly livered enough to allow the Germans to beat the russians and then have France get steamrolled by the German juggernaught.
If abwher is doing better they might be able to destabalize parts of the British empire and thus keep the Brits focused outside of Europe.
With these changes, and a good number of others, the Axis might, MIGHT be able to do as well as you suggest, but it would take them at least a decade, probably two or three to get that far though. Even then this is barely plausible, only a little bit.