Good morning,
It is interesting that your symptoms are triggered by the cold. I feel like my asthma is triggered by the cold - but it took a long time to diagnose it as "asthma". When I first went to my pulmonologist they didn't think I had asthma because while I had low lung volume in one lung my spirometry was normal. However, when I went to do the methacholine challenge it turns out I have severe asthma (which he says is triggered by allergies) but I have stopped going to cold places if I can because it triggers my asthma. I have a nebulizer that I use with asthma medicine at least three times a day if I am in cold weather. Have you tried doing that? Also has your doctor tested you EOS count or done the methacholine challenge test? I used to get sick and bronchitis and cough all the time especially in the cold. I am now much better after we did the testing and found the right combinations of inhalers. Plus if your eosinophils in your blood count are high there are different medicines that might help - at least in my case they did. I don't have RAD to my knowledge but I do know it took us a long time to identify the type of asthma I have which is eosinophilic asthma. I am not really familiar with RAD so not sure if that is helpful but just thought I would share my story in case it helps. Hope you find a solution. I would wake up coughing for years and was sick all the time in cold weather - took until the age of 42 to get officially diagnosed with this. I take spiriva and symbicort. I also do bi-monthly injections of Fasenra which has made a big difference. I had to stop using albuterol because it gave me hand tremors so everyone is different in what works for this. Just sharing my experience in case it helps.