I would not like to send a model beforehand in Russia. If you do, there is a big risk of things being damaged or lost. At least you better send it well in advance, it may take some time to clear the customs. But when travelling with a model box, I've never had any serious problems. Actually, once in Russia, travelling with models by flying can be easier than in the more civilized world. That's maybe because the people working at airports still know what aeromodelling is, and maybe because they don't care so much about safety regulations.
The last time I flew from Moscow to a contest in Magnitogorsk I did as I normally do, checked my box in the checked luggage. I must say it was quite scary to look how the box was transported to plane (you can see my box somewhere in the picture

)but in the end there was surprisingly little damage. On my way back I realized that I could have as well taken the model with me as hand-luggage, the whole russian team and some Ukrainians were there too, doing so.
Can you share more details about the festival? I just heart that the Russian Champs are in Moscow this year, in Khimki. I may go there. L