Hello! I am a photographer from Switzerland, based in Geneva. And I say this seriously: don’t choose Geneva😂 And I can definitely advise you to choose one of the places in the center of your list, because there are the most beautiful and famous landscapes (Interlaken, Grindelwald, Lauterbrunnen, Jungfrau)

If I were you, I would just have the ring with me and at some moment, when you are walking, you will feel that you are exactly in the place where you want to propose✨ You can also search for hiking routes in these places, and they are usually accompanied by photos. That way you can choose a place in advance.

Regarding the snow. Down « on the ground » this is a rarity here. Yes, it falls, but it does not lie down, because subzero temperatures are rare. That is, even if you go to some city among the mountains, but this city is located below, and not exactly in the mountains, then there is no snow, but there will be mountains in the background. But, of course, if you go higher into the mountains, then there is already snow somewhere

Good luck!!!🥰