I respectfully disagree. The secret protocols alone indicate that the USSR was interested in more than a simple trade pact.
The Soviet records are increasingly available in translated format. They are fairly clear regarding Moscow's intentions.
Acknowledging that Stalin was a completely rancid human being, and he probably plotted world conquest with his teddy bear at nights, I'm not so sure he could cash the cheques he wanted to write.
I could see a real possibility of Stalin overrunning the Baltic Republics of Latvia and Estonia. They hadn't been independent very long, they were tiny, their military and strategic position was hopeless, and there was no way to support them.
Lithuania he might try for. But that country borders both Poland and the German rump. The only route to it is through Latvia (unless he wants to invade Polish territory along the way). I'm not sure that either country would be happy with that. So that might be a bit too risky.
But would Stalin's campaign against Finland have turned out any better in this new Timeline than in the old one? I can't see that happening. Odds are, it wouldn't even go that well. Finland in our timeline was pretty much isolated and the Germans were holding their hands watching. Would the Germans be more inclined to support Finland with supplies and possibly troops, in the event of an expansionist Soviet War? With German concurrence, would France and Britain have rendered more aid?
As I recall the Soviet Union in the thirties, they were economically strapped, their recurring five year industrialisation plans kept imploding on them, and Stalin was busy relentlessly purging the officer corps and military to ensure that no one was going to replace him. The Bylorussians, Ukrainians and others hated the communists passionately and were on the verge of uprising. When the Germans rolled in, they were initially greeted as liberators in our timeline.
So.... what's Stalin going to do?
Maybe he takes Latvia and Estonia. That's fairly likely.
Maybe he takes Lithuania. But taking Lithuania might well be a Czechoslovakian-type line. If nothing else, its going to creep out just about every other major power.
Then what: Finland? The Finnish campaign goes no better, and likely goes worse. Assuming that the Finnish invasion is not crossing a Poland-type line.
Then what: In Europe, as I see it, he's only got two options - Poland and Romania.
Invading Poland potentially brings Germany into war. I can't see the post-Nazi germans tolerating a large expansionist Soviet state on their borders, particularly with their territory in Prussia divided. The Germans had spent four years fighting a war on the Eastern front, just twenty years before. I can't imagine they want Russia close.
If the Soviets invade Poland, what do the other powers do? In our timeline, they eventually responded to repeated German aggression by declaring war. My guess is that in this timeline, they'd eventually respond to repeated Soviet aggression by declaring war and lining up with the Germans.
In which case, we've got minimum, Germany, France, England going up against the Soviet, no two front war, no german blockade, no aid to the USSR, and likely when Soviet territories get overrun, the occupiers are treated as liberators because they are liberators. I don't think that the Soviet Union would do nearly as well.
So it seems unlikely that Stalin would invade Poland.
Romania? Possibly. But Poland is very invasion worthy geographically. Open country. Romania's a geographical mess, tough hill country, pretty rough to get through. So depending on Romanian resistance, it could be the Finland mess all over again. Romania doesn't have a border with Germany, but it does border on Hungary which is in the German sphere. And it does threaten the Balkans, which the British and Italians won't like.
So it may be back to square one, with World War Stalin, and the USSR coming out on the pointy end.
So, Stalin being a vicious thug, but not megalomaniacally stupid, probably wouldn't invade Romania.
Which leaves... what? Turkey? Next please. Persia? Well, that'll be a tough sell, and it'll guarantee a British response. Afghanistan? Flash forward seventy years to see how that turned out. Mongolia? They already own it. China? Possibly the only thing that could get the Chinese to throw in with the Japanese would be a Soviet Invasion - land wars in Asia, never a good idea.
Japan and Manchuria? Possible. But that's getting pretty far afield.
I dunno. Stalin was an opportunist with many malevolent intentions. But I can't see Soviet Expansionism taking place in the absence of Hitler's wars.
At best, we might see some form of minor meddling through funding communist parties and movements all over the world. But they did that in this timeline and it never really amounted to much.