I recently acquired a Sky Viper V2450GPS. It has a 720p camera connected to an embedded Linux board that has Wi-Fi on it, and has a micro-sized Pixhawk autopilot on board. It comes with a 2.4Ghz radio transmitter, or you can use a better one of your own. It runs the Arducopter code which has incredible features, most all of which are available on the little 2450. I got it on sale at Target for $99.95. I usually build my own but for $100, I can't even buy the Pixhawk by itself, much less build a whole platform with a camera. And, it runs on a single-cell lithium battery for about 12 minutes. My Iris+ is about a 15 minute bird hauling a GoPro and I've sent it 1500m away and had complete control via the transmitter and the laptop telemetry unit. The only reason I wouldn't send it a mile away is because my eyes aren't good enough to spot the thing that far away. My big hexacopter, sure, but not something that's little more than a foot across. On my big hex I also have a long-range video unit on that feeds me the video from the GoPro in real-time.
Were I in need of a drone for SHTF, I wouldn't hesitate to use any of mine, including the little v2450 that you can't hear beyond 10 feet away. I'm working on a better hand-launched fixed-wing at the moment. Once I finish that, I can pretty much surveil whatever size area I need to.