False. Germany in 1938-41 had access to almost all of the international imports it would need (rubber being a notable exception) through its ally in the USSR.
A couple of points. Early war (say over Czechoslovakia) means that the Germans and the Soviets don't share a land border to get all of these imports, and large parts of the Baltic freeze during winter. Plus, war at Munich means that the Molotov Ribbentrop Pact hasn't even been signed. Secondly, the Germans had to pay for those Soviet imports - often with military technology, industrial staples that could otherwise be used for the war effort (machine tools, locomotives, etc.), and hard currency, of which Germany had a limited supply (a large amount from plundering various treasuries, but not infinite).
Take a moment and imagine if Berlin had said, in early 1941, we've conquered the greatest prize in world history - which they had - and said that this is enough.
The rest of the 20th century takes a dramatic turn.
Alright, I'll take the bait. Britain continues the war. The United States joins at the end of 41 due to its alliance with Britain over Pearl Harbour. Even if Germany refrains from declaring war, Roosevelt finds a justification to enter (likely related to the ever-expanding Pan-American Security Zone, where US ships were escorting Allied ships and helping hunt German U-boats). Axis suffer serious setbacks in Africa. Germany is being heavily outproduced. Allies use their naval superiority to capture Sicily, Italian government collapses, forcing German intervention. Unlike our timeline, Germany actually has the forces to potentially force a stalemate in Italy.
Allies potentially look for other "soft underbelly" targets like Greece or Norway.
Soviet army continues rearmament. Depending on how strong/weak they feel Germany is, eventually they will either 1) launch a massive surprise attack against Germany or 2) test Germany's sphere of influence - say with further demands against Romania or Finland, or 3) put further pressure on Germany by restricting exports. So long as Germany doesn't succeed in actually making peace with the West, the bear is going to smell blood and prepare to attack. The only question is when this happens.
The events are different, but the result is the same.
There was no structural reason which compelled the Soviets and the Nazis to go to war. Babarossa was entirely born in the minds of a small cabal of men in Berlin.
Well, there were a few things which did mean the two were likely to be enemies sooner or later. Opposing governing ideologies, paranoia of leadership on both sides, running out of intermediary territory to split between them without stepping on each others' toes, aggressive foreign policies of both sides, German reliance on Soviet imports leaving them vulnerable, and massive military buildup by the Soviets which the Germans would not be able to indefinately match, meaning that delay would only see their foe grow stronger (similar dilemma to German pre-WWI).