Nov 10, 2019 - 10:50 PM
We did both trips from Luzern one month ago. The fastest route takes about 1h 15 minutes to Titlis, and 3h 20m to Schilthorn, which makes for a very long day. We got out & walked around, in snow, at Titlis for a while, but there isn't much to do at Schilthorn except go out on the big deck.
Pilatus(1h 10m) is also close to Luzern and at lower elevation, so keep it in mind, although walking around there is also limited.
Check the mountaintop weather cams for all of them before you go.