As far as i know "what if questions" are not encouraged here. There is a subreddit for that i think. So maybe you check out the search function.

Obvioulsy what if questions are hard to answer by nature but i will try.

Invading russia was pretty much the entire point of World War II so i guess your questions is even more "what if" but...

They would focus less ressources on the ground warfare and more on Luftwaffe and Navy. Then intensify their blockade and likely get total dominance over the channel and prepare for a landing. Then defeat GB somewhere in 41 or 42. From that on it can go in many directions...

The red army maybe invaded eastern Germany at this point already. They would be stronger and better structured than in 41. I guess its unlikely for Stalin to watch Hitler focusing on GB. Russia invanding eastern europe is a strong possibility in this what if scenario.

Sorry if this post breaks any rules, I'm on my phone and can't check the rules

That is a shame. This sub discusses history as it happens, and not what might have happened. Your question is better suited to /r/historicalwhatif.