It will take less effort with equipment than Barbarossa, so 1943 will probably be the next iteration in the East.
I'm looking more forward to crap tanks™ in 1941 though.
Ultradave will have a much better answer, but if I recall correctly, the blast wave from Little Boy at Hiroshima destroyed just about everything within a mile radius of the epicenter.
The end may still be quite some time away, but at some point either the russian military or the russian economy will slide past the point of no return and things will degenerate rapidly.