Oh, I have issues with other parts of that map as well like the desert, but the Hebra Mountains as you called it were definitely the worse for me. All the outer portions of that game are just too barren, which I suggest Rockstar did a better job at filling in the empty space with stuff like what we see in RDRII. I played like five hours of The Witcher and dropped it for something else (hated the movement when you're on a horse), but I definitely plan on going back in. Isn't the map (Witcher) for the PC like two times larger than that for the consoles? If so, that could make sense...I don't at all think BotW's map is too big. I think it is much closer to the proper size. The Hebra Mountains are more desolate (though I think the Gerudo desert is far more desolate)... like most extreme cold regions are. I still felt there was quite a bit to do there.
A game that suffers from that (and is still great) is the Witcher 3... I don't know the stats but that map has to be 3-4x BotW and double Orgins. None of them hold a candle to Just Cause 3 or Death Stranding. Those games are utterly enormous... and Death Stranding is basically post apocalyptic FedEx simulator.
The most underrated open-world game to this date is NieR: Automata. I also dropped the game for a Persona playthrough, but the combat is some of the best I've played with some of the most satisfying yet challenging boss battles.
E: I was in a game shop one time looking for retro games for a buddy and this guy was about to buy Death Stranding and I told him that if you like being a delivery man, you'd love that game lol. Very interesting concept story-wise though.