I can give you some more informations about Gstaad. It's correct that in October there is mostly no snow yet in the village. Snow normaly arrives during beginning or middle of December and normally we have white christmas. At least for the last 10 years, since I'm living here. September and Octobre is still a nice time to visit the area. Only November is very quiet.
Autumn time is wonderful with fresh mountain air, clear view of the mountains, great hiking&biking possibilties and cable cars open til end of Octobre. At the Arnensee you can experience a kind of indian summer.
Some luxury hotels will already close around end of September, but you wil find still a lot of offers, which will suit your wishes. Carriage rides will also be on wheels.
On Glacier3000 near Gstaad you can enjoy the high alpine mountains all year round. Husky tours are possible and a ride in the snow bus to the cabane. www.glacier3000.ch/en/Summer/
And some words about wintertime. Because Gstaad is not on this high altidude, big advantage to skiing is: you don't need a lot of snow to ski as in higher places. Ski slopes are on grass and not on big stones. So during bad winters it's possible there is better skiing in lower ski areas than in high alpin areas. And since more than 60% of the slopes are with artificial snow, there is skiing season from December to March in the lower slopes and November to Mai on the glacier.