Probably would have jumped at it a few years ago. Had similar concerns to you - a long and complex way of getting there for a short period. I did enjoy the Kamchatka trip but it was a bit of pain to organise. Also timing doesn't really work for me either. And I also have another Japan trip in mind - though not like we did last year. Good luck though if it does go ahead. Russia is an interesting place and I'm sure you would enjoy it.