The key thing when storing boilies is that they have room to breathe. Provided that they have been correctly dried after manufacture, they should keep indefinitely, though around 18 months is normally the accepted figure.
The problem with boilies occur for two reasons. One there is moisture after manufacture which means they have not been completely dried. This is aoften alleviated by perforating holes in the bag, but it is better if they are properly dried to start with.
Equally the real problem with boilies storage occurs when many bags are piled on top of each other, not allowing them to "breathe". This is a problem in humid conditions, when the boilies "sweat".
In cool Russian conditions, there is no reason why they should not keep for 18 months and more, provided the boilies are dry to start with.
In a perfect world, store them on racking about five high, but not more, with space around each pile of bags. This will be fine at a room temperature of under 10 degrees.