Are there longer power cords available other than the standard cord that comes with cameras? Or is it a cable we can purchase anywhere?
16 feet and 26 feet are available on Amazon. I have used both with no issues.
Any standard microUSB cable should work as long as the wire gauge is heavy enough for the length of run, AND the profile of the cable end fits the socket on the camera.
If you are looking for flat cables, these accessories from Wyze have 6 and 15 ft. cables respectively:
Here are some others that are known to work:
I’m really surprised at how hard it is to find flat USB cables!
Here are a couple of flat, but not super thin ones. I can’t vouch for the wire gauge being sufficient to avoid voltage drop.