The dog bite mileage looks to be within a mile or two of where we've had dog problems before, so likely the same dog or same owner.
You can bypass that area by riding around on Hwy 78. I don't know how traffic would be that way- I think okay to Milburn at least. It is 0.3 miles longer each direction to do that.
On Days 2 and 3, you generally head east into the rising sun, so consider a visor and daytime blinkies for extra visibility.
On Day 2, on the return, the scheme of this was to hit that section between Quinlan and Greenville late at night. You have some road sections and some bridges where the shoulder ends, and if you're fast enough to get there early in the evening, the traffic may be an issue. Regardless, make sure you're plenty lit up and reflectorized through there.