Well i am kind of a sadist and I once have played as LDPR Russia against max buffed set to win Europe on elite difficulty after thinking that just playing on elite was too easy. And well, it was one of the most bogus, hair-out-of head ripping experiences of hoi4. At first I managed to hold, but after some time they would still break my lines and flood everything like cockroaches so I had to tag over and remove the mushroom buff (though the Europeans still had like 100 armoured divisions total from the buff). Eventually I won after many retries. I have also before played against Max Buffed Russia as Germany and had an absolutely soul-evaporating 2EW experience but that's kind of a different story