That's one the few hikes in the nationalapark, which I haven't done yet. The hike into Val Tantermozza itself is short. In fact you could park the car right at the start of the path, and from there it's only about 1 km to the hut. I took the the train to Cinuos-chel-Brail and headed then towards Zernez. It's a nice hike, but... mostly in the shade.