Just wanted to close the loop on this. 5V did not work out for distance after testing. 12v does.
5v worked up to about 10’ of wire in testing. So if you have a short run, you could use that.
I used:
Power Supply: https://www.amazon.com/gp/product/B08C594VNP/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
Power Supply Splitter (I would not go over 4 cameras per power supply)
https://www.amazon.com/ZOSI-Female-Splitter-Adapter-Accessories/dp/B00KWWLEBK/ref=sr_1_3?dchild=1&keywords=cctv+wire+4+adapter&qid=1621525032&sr=8-3
Wires (Mine were already run, hence the desire to reuse):
https://www.amazon.com/ZOSI-100FT-Security-Camera-System/dp/B071GC2LTH/ref=sr_1_3?dchild=1&keywords=cctv+wires&qid=1621524851&sr=8-3
12v to USB:
https://www.amazon.com/gp/product/B08LPS3XHB/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
12v male plug to wires:
https://www.amazon.com/gp/product/B072BXB2Y8/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
Butt Connectors:
you’ll need a heat gun or lighter and crimp tool.
Setup has been up and running for 3 weeks now. works great.
You may be tempted to use this: (Kinda Works)
https://www.amazon.com/gp/product/B081NCXB2M/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
In testing, it’s capable of powering ONE v3 camera, but NOT two at the same time. So you can use it, which would let you use the 6’ of white USB wire if you like, but only power 1 camera with it if you do.
Wyze is missing a huge opportunity here to bundle and assemble a kit that lets you use v3 as home security cameras. Include a power supply, splitter, some wire, and adapters. I think it would sell.
Anyway, met my goal of replacing my 12 CCTV old cameras of meh quality with 10 v3s around the house now. Really like them!