You could try asking at
www.irv2.com. It's a much larger forum with a lot more members and posts. It's run by the owner of this site - and this site is an offshoot of IRV2's Winnie owners subforum there.
I"m sure folks have changed out lots of radios and electronics but not necessarily on your 2010 Tour model or maybe they have and not posted about it.
As for wires... they are strung everywhere roof, walls, floor. ETC. I think you'll find all the camera wires are in the ceiling.
Winnebago builds the roof with custom Styrofoam blocks that route Air to and from the A/C units and each block has wire channels custom molded into the blocks. There is not much if any info on where those channels are.
Summing up... in general you will be on your own but it CAN be done. Perhaps start with the radio. That should be easier. Most radios come in DIN sizes: single, 1 1/2 or double. Find yours by model number and then look for replacements.
Here's a suggestion I make to a lot of folks that want to do what you want to do - take the RV to a Professional Car Audio retailer/installation shop. They'll know what works and how to do it.
Since you're in Montana, that may not be so easy. "Auto Trim Design" in Helena says they do that kind of work. Also "Auto Concepts," "Ron's Automotive Specialties" and "Barreta Audio" all claim to do Car Audio work in Helena.
Auto Trim Design of Helena Welcomes You
https://autoconceptshelena.com/
College towns like Bozeman are best choices - I know it's 80 miles away but Bozeman has 3 or 4 dedicated Car Audio places.
Sometimes a call to Crutchfield for some advice can be helpful. Good luck.