You're a better man than I. I have often thought about redoing the coax under the house. But, I just can't bring myself to crawl around under there.
I still might do it someday. It would be a beautiful thing to have new coax and add cat6 to every room. OTOH, I could do it through the attic, as well. So, I may go that route. It's hot as hell up there. But, it beats squirming around on my back with subfloor in my face for hours.
Luckily my house is a mobile home and my dish is on a pole about 30 ft from the house. The most I had to do is re dig the trench for the coaxes and my node and other ota diplexors ,etc are under the tail end of the house . So I didn't have to crawl under it, like I do when I have to re-level it at certain times. The most work was the trench and trying to figure out which coax goes to what room. I should of just labeled it a long time ago , so any changes would be easy. Now it is . I can't wait till Thursday morning , so I can get my second hopper up and running.