My first dry resting of dens was last Oct- Feb. I had OK results and flowers on many of mine that did over winter. Not all though. I will be even more stingy with water next winter on mine and encourage you to resist watering as much as you can.
My superbum, parishii, Little Sweet Scent and Nestor 'Sweet Fragrance' got watered 3 times and I think that was too many times for them. Next winter, I may not water at all. Mist a couple of times only.
I sent BD a couple pots of keikis this spring.