This subject raises a lot of questions with no firm answers available.
The winter of 1941-42 was the worst in Europe in 50 years. The Germans would have been better off if they had avoided it and invaded in 1942 instead. They would have had another year of receiving grain and oil from their Soviet not-allies, under the Non-Aggression Pact. This would have given Germany another year to prepare, with better maps, more winter clothing, and more security in the Occupied territories in Poland.
On the other hand, many other things were happening during this time frame. Would Germany have gone ahead with Operation Sea Lion (amphibious invasion of Britain)? Would USSR have attacked the Germans in Poland and then tried to attack Germany? Could Germany have reached the Suez Canal with the Africa Corps, given that they also didn't have to supply an invasion of USSR at the same time?
Inquiring minds want to know, but never will....
Steve