I dont know what is your area like but i can give you some general rules... keep it cold... arround 5°C in the winter. If you cant provide that low temperatures than i suggest you put them in the fridge. this should be fine. just make sure they are dry, and check them from time to time and as soon they begin to grow. pot them in the media.
I stored mine in the unheated garage. it work fine with me, but the temps can go very low here.... even -20°C.
in the garage of course not... but they stay above 0°C.
P. formosana is not difficult to grow. its not that picky. just make sure the temp are below 10°C
post some pictures next year.
I love pleione btw
this year i ordered a bunch of them. cant wait for the next year
regards
Gregor