Thanks for the "thumbs up".
I poked around for some more info on the accessory camera system option and discovered it can be retrofitted to 2014-16 GMs as long as they were equipped with the trailer towing side mirrors. It's a dealer installed option so anyone that has a 2014 or newer GMC or Chevy 2500/3500 that came with the larger towing mirrors can order one or both of these kits and either DIY the install or have someone do it for you.
The tow mirrors are required for the turn cameras and those trucks will have the software and WiFi rcvr already installed to allow the display to interface with the cameras.
Here are some pictures I poached off the GM corporate site showing the components:
camera mounted on side mirror
Display menu showing camera positions that can be selected. The "other" icon would be the fourth camera mounted inside the trailer.
example of a multi-screen view
camera mounted to back of trailer. Signal is WiFi at 2.4 ghz and the camera has infrared lighting to deal with low light if your trailer doesn't have back up lights installed.
There are two kits. The first one consist of the two mirror mounted cameras and a third camera that mounts to the back of the trailer. It retails for $999. The second kit consist of a single aux camera that can be placed anywhere you choose (mine is going inside the trailer). It retails for $349. I'm pretty sure either kit can be had for less, my dealer included both kits installed for $1000.
I saw the other thread discussing a DIY surround set up and these WiFi cameras might be an option for owners of other brands of trucks. The cameras are made by Echomaster for GM.
You seem to have a great attitude about the experience
I try not to get bogged down by the little stuff (life's too short and all that). In my experience it helps to keep a good sense of humor so you can laugh about all the craziness instead of cringe everytime you think back on it.