Past master wrote:

I'm also told they keep the motorways clear

Swiss Alpine Winter Driving
Motorways: Throughout CH motorways are kept "open" in winter, but that does not mean they are cleared of snow and you can see black tarmac, especially in heavy continuous downfalls of snow. Drivers are expected to be experienced and vehicles equipped to cope with the conditions.

Mountain Passes: Almost all of the mountain passes will be closed starting from mid October through to April. Actual dates vary depending on the individual pass altitude and prevailing weather conditions. The "Simplon Pass CH>IT" is CH's only 365 open high altitude pass and in the very worst of conditions you will need chains there even in a 4x4 with winter tyres - all the other cross border passes rely on the tunnels beneath.

Mountain Roads: those leading to high altitude villages will most certainly be covered in snow and require proper winter tyres and/or snow chains. They will be subjected to snow clearing operations - and obviously ski resorts are pampered (for commercial/financial reasons). However our mountain village is not a ski "resort", and as an example, you will not be able to get into our village in winter without winter tyres fitted and 4x4 drive, and that's despite the road being snow "groomed" every morning starting at 05:00hrs. It's narrow, steep and almost single track with a couple of 90° blind bends, and in places a sheer 200ft tumble. One person lost control last winter - car was scrap - they were hospitalized. So take care.

Snow Chains: finally, should you need snow chains remember that they are very much cheaper to buy in the UK than in CH, and I understand that you can even rent them. Secondly, practise fitting them before leaving the UK - fitting them for the first time in minus °C in a blizzard where you can't see the end of your nose does not make for a safe attachment! Thirdly, in almost 40yrs of driving in winter through mountain regions across Europe I only once required snow chains to retain mobility in a 2W drive car. I and my traveling companions just sat it out for 72hrs in the warmth of a local hostelry. So don't be alarmed or discouraged - driving through a snowy alpine landscape on a sunny winter's day is exhilarating not excruciating - so long as driver and vehicle are properly prepared to do so. Enjoy your drive.

Using winter tyres is a must when you are driving in snowy or icy conditions. Usually I travel every winter to the central Europe mountain range for the last 6-7 years and actually I used chains only once. Even though I am based in Greece I use winter tyres for the greek mountains , as well as for my trips to Europe. I use the RUD centrax chains (spider chains) that fit Freelander 2 front 18'' wheels.

Freelander2 has a better overall behaviour in snow - sand than discovery3, but when the land is extremely uneven and one or two wheels are in the air then you need speed to overcome the obstacle. Disco3 can really go slowly over the obstacle, which makes the difference in off road conditions.

I think that's very sound advice from Athelstan. As I said, I'll be sticking to the motorways and I don't have a problem driving on snow. But yes, if you're going into the mountains remember that the passes are closed - no point in keeping them open when there are tunnels underneath - and yes chains are a must. If you've never used them the difference they make is amazing.