Hi, I wanted to provide an update on this because I've been developing primarily on Windows for both iOS and Android. There are now development platforms out there that allow you to test iOS apps from within Windows on your iPhone.
The one I have been using extensively is the Expo SDK which I can use with Expo CLI and the Expo Go app to run my React Native application on my iPhones and Android Devices from Windows.
The only issue I have found is that while I can build iOS apps from Windows, I can not upload them although I haven't done to much research in to this as I just use my Mac to upload via the Transporter app.
Hope this helps.