I have been to Siberia. Russia is the largest country in the world. Most of its coastline is undeveloped. In my view, they are more advanced in terms of Arctic oil and gas drilling and transportation than we are, and they have many decades to go before they have any problem with their own deposits running out offshore in the Russian exclusive economic zone. You are correct in that their onshore land deposits are becoming exhausted, but they have vast maritime zones and that's where they are going.
To take your question a bit further, you might have asked the same question about China. China, as a rational actor, as a nation state, has realized that it can use foreign investment and trade to get the resources it needs from other countries. That's what they are doing in Africa and in Latin America, and indeed it is why several Chinese state-owned companies have invested in Canadian resources. I don't regard that as a threat, provided that the normal national security protections are in place.