Thanks! I decided to do with your MotionEye OS suggestion. It was simple to set up, and I am impressed so far.
I've now had it set up for a while. I set it to do videos, though it was set up for images while I was testing. It may be trying to do images and video... nothing interesting on the images. the motion sensitivity may be too high.
The images seem to be fine, but all the videos are either 0 byte files, or corrupt/unplayable. any suggestions? It also seems to drop off the wifi (built-in Pi3 wifi module) a lot.
My two thoughts so far are 1. perhaps using the camera, pi, wifi, and writing to memory card uses more power than my power supply can put out (700 ma at .5 volt, under recommended 1 amp). 2. Perhaps my memory card is too slow, causing aborted/failed writes. Any other suggestions would be greatly appreciated.
I will try running the setup directly from a battery (so pure DC, little/no noise) which can output up to 3 amps at 5v for at least a few hours. That should rule out (or confirm) any power supply issues. I will update with results.