Short answers, pulled from the story.
The Soviet military command declared the period from the 5th of December 1941 to the 7th of May 1942 as a specific winter campaign. This timeframe marked the commencement of Soviet counter-offensives following Operation Barbarossa.
Major operations included the Moscow Strategic Offensive Operation, the Kerch-Feodosia Amphibious Operation, and the Demyansk Offensive Operation. The Rzhev-Vyazma Strategic Offensive Operation also took place between the 8th of January 1942 and the 20th of April 1942.
Extensive fighting occurred across central and northern European Russia with key sites such as Tikhvin, Klin, and Rostov recaptured by Red Army forces. Southern theater campaigns involved critical attempts to regain strategic ground in Crimea and the Barvenkovo-Lozovaya region.
Red Army mostly failed to encircle German units because Germans managed to avoid significant casualties during this initial phase. Commanders prioritized maintaining operational flexibility over holding every captured position which allowed forces to regroup while inflicting attrition on attacking troops.
The Lyuban Offensive Operation lasted from the 7th of January 1942 until the 30th of April 1942. This offensive stretched over four months ending only at the end of April despite logistical challenges facing Red Army units.