I have flown there in a Bonanza on the way back from a holiday in Spain, Chambery was our stopping off point, it's about 1/2 hr from there up the valleys. You would need to be familiar with the area as it is fairly easy to pick the wrong valley with disasterous consequenses. I would say to do it anything other than reasonable VFR is asking for trouble. And to get into Chambery in marginal VFR is risky (its surrounded by mountains). Technically all you need is the courchevel sign off and to be within 6 months of your last landing there. Go on nice day and its an awsome experience.
GG