Ultimately the readers must decide for themselves how to interpret what Hemingway observes in these essays, and anyone who might want to be an artist or writer should think twice before they draw some of the same conclusions. Hemingway is correct in much of his art theory, unsurprisingly (he is a master of the craft after all), and his observation that artists tend to abuse hard drugs and alcohol is a well-established connection. However, just because opioids are historically popular among artists, that does not mean that artists should do hard drugs, and it does not mean that artists must suffer to create art.
Now, Hemingway notices that during the winter he spends in his cabin, when he is faced head-on against nature's cruelest season, he notices that his ideas flow freely and beautifully. This reminds him that suffering often has brought about some of his greatest art. But the reader should notice that Hemingway missed several other interpretations of this fact: For instance, perhaps Hemingway is solving many unfamiliar problems in his days at the cabin, and perhaps that helps get his creative engine running. Perhaps it isn't suffering that brings art, but struggle, and maybe winter is a season that naturally demands struggle.
The point here is not that Hemingway is wrong about his observations, but rather that although there is certainly a relationship between artists and depression, between artists and heroin addiction, between artists and alcohol—that those things don't need to define a person's life in order for them to be an artist. Instead of doing drugs, a person could simply travel to a cabin and work hard to survive, as Hemingway's own example indicates.