I know the question is kind of vague but I recently stumbled on some [Red Army Christmas jingles](https://www.youtube.com/watch?v=52GsqHvrPBg) and it's got me wondering how common the celebration was among the common people; if the elite secretly indulged despite an Atheist creed etc. Maybe if the divinity of Christ was downplayed but he was still somehow observed etc.
Basically any insight around this subject would be interesting, thank you!
The Bolsheviks initially tried to find an alternative for Christmas with a new meaning, something that would celebrate the Soviet Union, the Soviet people or the communist cause. They tried to undermine Christian holidays by organizing a 'Red Christmas' in 1923, where people would dress up as Allah, Buddah, Egyptian gods and Orthodox priests. The goal was to demonstrate how irrational religions were and how these different faiths could not all be true. However, these parades were accompanied by burnings of religious scriptures and other activities that were deemed offensive by the public, so 'Red Christmas' was abandoned.
So their next step was an atheist alternative to Christmas.
Officially, the Soviet people celebrated New Year's instead of Christmas. While at first, any symbolism associated with Christmas was banned, the Soviets eased up and rebranded things over time. In 1935 they allowed the return of the Christmas tree, only now it was simply used as a New Year's tree. The celebrations included putting up that tree, decorated with ornaments and a red star on top, and children getting presents from Ded Moroz (Grandfather Frost) and his granddaughter Snegurochka ('snow girl'). Ded Moroz could be described as the Slavic version of Santa Clause and was initially banned in the Soviet Union due to his historical ties to Christmas, but they allowed this figure to return to Soviet pop culture to appease the masses. The Soviets failed to assign any new meaning to the holiday, so they repressed and redefined any religious connotations and by the 1930s, New Years Eve had simply become a festival of fun and leisure. People got together with family and friends and prepared homecooked buffets (fun fact: A staple for New Year's was and still is olivier salad). There were also public New Year's celebrations, where (in the 1930s at least) children sang "patriotic" songs thanking Stalin for his work. Over time, New Year's became the most popular holiday in the Soviet Union and still is in modern day Russia. To outsiders it simply looks like Christmas because it has become very similar, but it isn't the same. It is not a celebration of Jesus, it is a celebration of the new year, family, fun and good food. To this day there is this "superstition" in Russia that the next year will go according to how you start it, meaning that having a lot of food on the table on New Year's Eve means that you will always have enough food in the new year.
Religious groups, and especially Christians, were persecuted in the Soviet Union. Some of them tried to operate more or less in secret. Houses of prayer were destroyed by the Bolsheviks and religious authorities were exiled, imprisoned or shot, so orthodox monasteries had to adapt. They operated, as Jennifer Wynot calls it, "without walls". There are accounts of them celebrating Easter in prison, so it isn't far-fetched to assume that they at least tried to celebrate Christmas in secret as well.
There is also a museum in Detmold, Germany, which is about the cultural history of the German minority in Russia. I went there last year and they had a small exhibition about secret religious activities of the German minority. On their website, they mention that not much is known about that because of Soviet propaganda. In line with that, I could not find any definitive sources about how common secret, non-secular christmas celebrations were or whether the elites celebrated it. Maybe someone with a little more expertise in this field can add something to this.
Sources & further reading: