I don't think that the Russians could've forced the Germans back more than temporary in winter 41 and spring 42. The Germans were far to strong and the Russians to unskilled in mobile offensive warfare to encircle the Germans and be able to hold them inside for a longer time. That do not exclude the possibility that with a more limited offensive the Sovjets could have taken some key areas and jammed the German summer offensive a fair bit as well as having more forces left to fight said German offensive.