We've been in the chalet at Hirmentaz for 3 weeks in summer 2019 with 7 persons (four adults, three teens).
The chalet is very nice with everything you need for such a group. Four sleeping rooms (one with bunk beds, the others have double beds), two toilets, a bathroom with waching machine and dryer, a kitchen with everything you need including a big table, a nice living room area and a nice place to sit outside.
The chalet is the top most of some others, situated at maybe 1300 meters right below the peaks of the Hirmentaz mountains. Hirmentaz itself is a very small village mainly for winter sports tourists, in the summer it is really calm. There are some herds of cattle around and the farmers came for milking in the morning and the evening, and some other tourist in the chalets nearby, that's all.
If you like nature & hiking the region is perfect: many mountains around 2.000 meters high in the area, even the Mt. Blanc is just an hour or so away by car. On the other hand it's just 40 minutes to the Lake Geneve and Thonon les Bains. If you like swimming in really cold rivers there's a nice place near Bellevaux at the wooden bridge over the river Brevon. Its also a good region for road & mountain biking, rafting and climbing. There are some nice markets in the villages around, in particular at Boege. There is a tourist info at Bellevaux which is helpful.
Shops are 5 minutes away by car at Bellevaux and Lullin, two big supermarkets at Saint-Jeoire are 25 minutes by car. In Hirmentaz there is a bar where you can order bread for the next morning.
The landlords, Mme. and M. Favier-Bron are very nice people and very helpful. They speak french, but their daughter speaks english fluently .
We really enjoyed the place :)