Dendrobium Nobile - out of season? When to repot?

[Mountain Kat]

Purchased a dendrobium Loving Memory Fizz in bud . the flowers have now faded and some of the older canes are dropping leaves. There are several immature growths and a keiki that bloomed with an additional immature growth. Now that it is fall, I was thinking the plant needed winter rest - but with these immature growths - maybe not?

This is my first Den and I am new to semi-hydro. My questions are: should I leave in old pot, reduce watering and rest? Or should I repot and keep watering and put on seeding mat? I also just put up grow lights to augment my light for the winter months here in Montana (yes, everything is inside). Finally,should I repot the keiki now?

Thanks so much.