The answer did come back on automatically when I disconnected the wifi for a short period accidentally. Not sure of how many feet but I have cameras placed on cabinet inside facing outside and it will recognize a face in the street. I delete each day so I am unaware of how many days a SD card will hold on it. Personally if you want a more high tech indoor/outdoor system I would not get it. Not user friendly on my phone, but I do really love the Arlo system by Netgear that I have installed at my home and it is completely wireless, but does cost more. This system is at a rental property for temporary usage.
Hope this helps.