iirc the claimed range is around 8km on the one i have, about 5 miles. I have assuredly gone well over 2km with no issues with control or video feed. This was over a straight highway. I routinely fly around a kilometer away, and the only issues i have is if i launch from an extremely dense patch of pine trees, and only at about 800-900 meters, i will lose video (artifacting for a second), but not control. It's never had to RTH.
In case you're curious about city usage, i have a friend that has one he launches from a culdesac in Orange County and can fly in nearly any direction for about 8 minutes* before he hits a geofence, the drone still functions normally. If there is any issues, he can just fly higher.
The newest newest DJI stuff claims even more ridiculous range, 15km+ over open water, for instance.
If i hadn't used it myself, i wouldn't have believed it, it sounds like BS.
* this is 5-7km depending on the tailwind