There is supposed to be new snowfall tomorrow night and Friday through out the Central and Eastern Switzerland. It looks like Andermatt has gotten the brunt of the recent snow and the weather is looking best in that region, so that would certainly not be a bad call.

Flims/Laax, Lenzerheide, Davos etc are all looking like having some sort of cloud cover on Saturday afternoon. This might sway me towards Andermatt for Saturday, and then somewhere in Graubunden on Sunday (when it will probably be a little cloudy everywhere). I will leave my final decision making 'till as late as possible on Friday to get the most recent weather forecasts.