Same softy chickens here. They just don’t like to walk into a snowwhite world. And rather stay in the coop with a small attached covered run (all together about 3 m2 for 7 bantams).I agree with Cluckmecoop, my chickens don’t like it when snow is covering the ground and stay in their coop. Fortunately for them, we don’t get much snow here in North Carolina, and even then, it often melts and does not stick.
We have mild winters in the Netherlands too. Last year we had 8 days with snow and below freezing. Most winters its cold for a week or so without snow. If it snows it often melts again after a few hours or a few days.