Hi, you might like to check out the website of the
British Embassy, Moscow, if only because it gives contact telephone numbers, and if the information is not readily available on the website you can phone and ask them about the current delays for settlement visa interviews.
The delays vary very considerably around the world.
You do not say when you are planning to marry but if there is a delay in getting an interview of a few weeks or months then you might like to ask whether they will accept an application for a spouse visa
before the marriage has taken place.
Certainly the British Embassy in Bangkok allow you to submit such an application, as long as there is a covering letter saying that the marriage has not yet taken place, it is expected to take place or or about (date) and could they kindly allocate an interview date on or after (a slightly later date). We did this back in 2001 and my wife had her visa interview just two weeks after our marriage, at a time when there was an eight week wait for settlement visa interviews. All the required evidence was simply taken along on the day of the interview.
Do Moscow allow the same procedure? If so it might cut down your wait.