The Ward family no longer could afford to keep it and they now sold it to the National Trust, but they still visit frequently and are allowed to stay there in one of the apartments upstairs.
Indeed winter is hiding from Winterfell right now, but that is also one of the reasons they chose Castle Ward. Because winter was still on its way and they did not want to make it look too wintery or something. The tones in the TV show are a lot more grey and tuned down though. Most days in Northern Ireland are a lot more gloomy though. I was lucky to be there at such a sunny and warm day :)
Oh the guides had so many stories, especially about servant lives. Very interesting and also I had not seen a place that had so many original items from the past preserved, basically the place felt barely touched by time.
Thank you so much @warpedpoetic!