Is it safe? Before going off-piste always do the checklist
As soon as a northwestern storm occurs, this area is go! This means that the whole of Southern Germany is getting a lot of snow, including the Kleinwalsertal. An immense load of snow can fall in this region, as long as the depressions come from the north to northwest. In case of a weststau, Oberstdorf and the Kleinwalsertal will get some snow but due to the high snow line caused by high temperatures, this snow will get wet, in which case you should wait for the cold front to arrive. It's pretty unfavorable when a southföhn arrives. This will let the snow disapear very quickly. The main advantage of this area is it's grassy surface, which makes this area perfect for some early season fun!
It would be best to go to the Sollereckbahn. This area has some very nice treeruns and it rarely gets crowded around here. Not the most challenging terrain, but at least it isn't a wildschutz area.