Ryukins and Shubunkins in the winter

[C-Note]

I know I'm way ahead of schedule, but... I live in the Pacific Northwest, where winters tend to be mild. We may get a thin layer of ice on top of our pond, at most, but we keep the waterfall going, so it's never completely frozen over (the birds thank us for that!). I know my koi do fine there through the winter. We stop feeding under 50 degrees F. But what about my awesome Ryukins and my large Shubunkin? Can they winter out there without food, as well? Or should I plan to set up an indoor home for them, and keep them warm and fed year-long? We had one Ryukin do fine over the last winter, but then a crow nabbed him in the spring (we are still heartbroken over that one), but I'm not sure what's best for them. Thanks for any advice!