OP, Clearly you've done research and you know that there are risks.
I completely understand want to show your children the land of their birth. Our daughter was born in England while my husband was in the Air Force and we were stationed there. We came back to the US when she was 18 mos and she desperately wanted to see England. We were able to take her when she was about 10, but obviously a much easier trip than to Russia.
My husband fought the Cold War in the 80's at a base with nukes and the only model of planes capable of both carrying nukes and reaching the Soviet Union. His base had a big billboard size sign at the entrance reading "The mission of ...[this base]...in time of peace is to prepare for war and DON'T YOU FORGET IT!" So, my view of Russia maybe skewed. It's just that Putin seems to want to put everything back to the way it was in the USSR.
So, take this in the spirit is offered and knowing that I may be overly distrustful of the Russia govt:
Personally, I would skip this port.