Dendrobium Sa-Nook with crumpled leaves and drop leaves

[Vespucci8]

Hi all,

I have a dendrobium that has finished flowering. I may have made a mistake by repotting these after flowering, while it's winter. After that, almost all leaves became crumpled with strange spots and then fell of. It is wintery here at the moment, with snow and little daylight.

Indoor temperature is 66 Fahrenheit (19 C) and humidity is 50%.

Can someone tell me if this dendrobium can still be saved? Are there new pseudobulbs growing in the spring? And how many times should I water it? When the potting medium is becoming dry?

Best!