what is gonna happen if u didnt destroy Russia before winter cold?
Do you mean "What will happen if Russia is not destroyed before the end of winter?"
If that is the case, well, there is no way to finish off the Soviets before the end of winter. First, they have at least twice as many units along the front than I have. Second, the combat penalties in frozen/winter climate are favorable to them (by ~30%). And finally the fact that there is a No man's land (of provinces with a very low infrastructure) are preventing Germany as well from breaking through.
Now that it is clear that the Soviets won't be destroyed before the end of winter, what will happen when spring will come? I am not sure yet, mostly because there is a not-so-secret-now operation being prepared on the Axis side.
If it fails (or if it doesn't happen), then I expect a very strong offensive from the Red Army. Between Leningrad and Moscow, I think that the Heer will be able to hold the line. Farther in the South, the Axis doesn't have enough units to prevent the Reds from moving forward and reconquer all the provinces East of the Volga river (this may even happen before spring), especially with so many units belonging to Germany's satellites. Then, we will be heading to a campaign of attrition.
The Western Allies are not a threat for now, just a nuisance. They just can't stage a D-day in Europe with the current balance of forces along the Atlantic coast.