Lots of talk regarding detecting the remote infrared signal. How much information does the TV feed through the HDMI port?
Regardless, I'm not too worried about volume but a camera watching me to determine if a dog is in the room is creepy. However, a camera seems easy to defeat. Put a piece of tape over the lens.
If doing that somehow disables the remote control, then I would put the DVR inside a cabinet and buy one of those IR repeater devices that are designed to use a remote in another room. I'd just use it in the same room by sticking the blaster inside the cabinet with the DVR.
If the DVR is smart enough to require a heat signature in the room or it doesn't work, that would be harder to defeat but not impossible for the determined. One could quarantine it a spare room and use pillows wrapped in an electric blanket. Of course if it periodically requires the heat signature to move or it gets sophisticated enough to detect breathing/pulse ...... maybe it's time to quit watching TV!