What if Stalin heeds the warnings but instead of attacking like the other thread he digs in his troops, has all his weapons manned and basically just gears up for war.
Really digging in doesn't do you any good. What he needs is mobility and the willingness to use his strategic depth. Pulling back to the eastern Polish border and fighting from the 1939 positions there (which were much stronger than the inner Polish works of 1941) would be a big help. Avoiding stupid, pointless 'stand and die' orders also helps. Preserve some of your frontline forces for the late 1941 battles. Just dig in, and the blitzkrieg pockets you, and then the German infantry starves you out and pries you out.
Really whats needed is for Stalin to be more realistic. Hard to do for a guy who everyone has learned to be afraid of telling the truth.
After that, its keeping your forces alive until the NCOs get enough experience to fight effectively. The purges have gutted your officer and NCO ranks, you need time to rebuild that capability.