(I think it's a very nice custom that makes people think and be grateful for what they have).
Usually it's only the closest family and friends who accompany them (also depends on how many people the wedding train of cars have room for).
The rest of the guests only join at the reception .
The guests who are present give flowers to the bride, and drink a bottle of Champagne.
Nowadays many couples opt for a marriage in a church but church marriages in Russia still do not have official status, and the church requires a civil marriage certificate to arrange the ceremony for the couple (the couple must be officially married by ZAGS before the marriage in church).
Usually it's only the couple and the witnesses in one car but sometimes it may be two cars and the closest friends (seldom family: they must take care of the reception).
The couple visits memorials in memory of people who died in the World War II or Russian Civil War of 1918-1922, other famous graves or memorials, and lay flowers there.
There are posters with jokes about family life and wedding all over the walls on his way up made by the bride's friends.
Each stair-well is a challenge for the groom - he must answer a question to be allowed to make those few steps up.
If he guessed wrong, he must pay cash to pass this stair-well.
(If the building has a lift it will be usually blocked by the bride's team; but if the groom manages to find another way to the bride's apartment than the stairs, it's his right.
Most couples wisely opt for a shortened version of the church marriage ceremony.