Khazaria surviving would have wide-ranging effects on Eastern Europe. Primary among which, I think, is that the Russian principalities would have been shielded from the mongol steamroller. The way I see it, this would have two effects:

1. The Russians wouldn't be weakened enough for the Lithuanians to grab all their land, so your Hungary-Poland might exclude things like Galicia.

2. On the other hand, the Russians would never have a reason to unite, so they'd probably be shattered into little principalities anyway.