A 'successful' Winter War would be a really bad thing for the Soviets... It could well lead the US into thinking "Well those guys suck just as much as the Nazis!" and lead to less or even no lend lease for the USSR. It also might lead to a three way war if Stalin becomes belligerent or Churchill gets cocky in Caucus mountains and Northern Iran. Occupying Finland would also imo tie up many more troops than OTL where the Finns stopped at a pre set line and the Soviets knew they weren't going to move any further.
So the SU might be a bit stronger in the very start but if Barbarossa plays out in any way similar to OTL they will be FAR weaker in the long run. By the time 1945 rolls around I can see Germany still being pretty deep into the Ukraine / Russia. Maybe being a bit stronger but probably a bit / a lot weaker having fought just as hard with more territory to occupy and the Western Allies grabbing more territory quicker after they break out of the Normandy hedgerows.
So the SU might be a bit stronger in the very start but if Barbarossa plays out in any way similar to OTL they will be FAR weaker in the long run. By the time 1945 rolls around I can see Germany still being pretty deep into the Ukraine / Russia. Maybe being a bit stronger but probably a bit / a lot weaker having fought just as hard with more territory to occupy and the Western Allies grabbing more territory quicker after they break out of the Normandy hedgerows.