It might be to late but we just returned from St. Moritz over this (19th) weekend and it was beautiful. I think the coming weekend there will be the Polo going on so might be really busy. But the trails were open, most and conditions great.
Incase you need a Hotel, I would fully recommend 'Laudinella' they have a spa/sauna that you can use after a days skating (and very close to the trails 3mins walk).
Too far for you, but all the runs in the Jura mountains, JU, NE, VD are opened and in excellent conditions- the whole of the GTJ in fact. The Grande Traversée du Jura is a long distance x country run, from almost Geneva to almost Basel. The massive advantage there is that the runs are on top of the flat crested Jura- and the views of the plain, France and Switzerland and the Alps, are just magnificent. And much much less crowded too.
I live roughly in the middle- if anyone wants info re accommodation, rentals, etc- feel free to contact me.
If you are looking for just a day's ski, then as well as Einsiedeln, there is Rothenturm or Ricken. Both these have 'Club Houses' with snack bar, gear rental, changing rooms and you can also buy daily or yearly Swiss langlauf pass.
I was in Leysin all weekend, super downhill snow and the cross country looked spectacular and totally empty..
I stopped on the mountain at one point, around 10.30, half way down a long run where I could see all the way back up and down.. I was alone, just silence..
We're looking for something different next weekend - what's near you? Two skiers, one kid for snow garden, one wife for shopping or spa?
x country or downhill? The Jura is not a good mix for ski + spa + shopping.
How about going to Ovronnaz and stay at the spa (Les Thermalies). Or a bit further at Loèche-les-Bains, and again, with several spas. Hôtel Bristol is great and not far from cable car to Torrent Bahn, and has its own small spa.