The short answer is: Geneva.
The long answer is: You should almost always fly to Geneva.
The main problem with flying to Chambéry is that the runway runs North to South in a very deep valley and is at the end of a lake (the lac du bourget). As you may know, valleys can “trap” cloud. If you have ever skied on a nice sunny day and taken a look down at the “sea of clouds” in the valley below you will know what I mean. As you may also know, areas around lakes can get misty, the so called “smoke on the water” effect. So if you combine the steep mountains, low cloud and mist, you will understand why the runway is often shut at Chambéry airport in the winter (the real reason will need to be explained by a pilot as it has something to do with a visual approach and lack of equipment at Chambéry).
The second biggest problem with Chambéry is that it is tiny. There are 2 luggage carousels and what often seems like only 2 people to put luggage on them. Therefore, if 2 aircraft arrive within a short space of time then you could end up waiting an age for your luggage (this happens all day on Saturdays).
Another issue is that if you are heading towards the majority of big ski resorts from Chambéry (Three Valleys, Paradiski, Espace Killy…) then the road from Chambéry to Albertville can be a nightmare on Saturdays, with huge delays caused by traffic jams.
It is not all bad. If you fly to Chambéry on any other day than a Saturday and the weather is fine and your flight is on time, then you will be on the slopes in record time. However, if you are planning to fly on a Saturday, or you play by the law of averages, then you are best off flying to Geneva as the often advertised 45 minute reduction in journey time is unlikely to happen.
Let us know if you have had any good or bad experiences flying in to Chambéry and heading to the slopes!