A more powerful repeater alone is not likely to help the situation. Remember, WiFi is bi-directional and the signal that we want for improved range come FROM the P2V. A more "powerful" repeater alone is not going to help. Here are the things that would provide better range:
A higher gain directional antenna on the repeater, but the trade off is a a reduce "beam width" meaning you would really need to always keep the antenna pointed directly at the P2V.
Increased TX power power on the P2V (perhaps via a firmware modification), but this would ideally be matched with an increased TX power on the repeater too.
The manual says that the range extender has an RF power output of 17dBm, but does not provide any information on the camera's RF power output. I'm guessing (pure speculation) that the range extender has a 5 dBi directional patch antenna built into it. If so, that puts our EIRP at 22dBm. This is WELL under the FCC allowed limit of 36dBm EIRP, so there is definitely some room for improvement.