We did a similar run to Luckenbach last year. We actually went out through Dripping Springs on Fitzhugh Road to Fredericksburg. That's a fun ride - including a wet creek crossing! Some of the San Antonio folks met up with us in DS and even took us on a detour on Crabapple (??) Road that was really fun.
Could do that. But we all just did the Three Sisters last month at the Kerrville GTG (SSITHC). In fact, I did it twice: once in the group and once by myself - 1 hr 35 mins for all 100 miles. Not fast because I didn't know the road and it is REALLY rough, but good enough for a 1st time.
I forgot about Kerrville just having taken place a short time ago. I haven't ridden the Three Sisters since some time around 2012 or so. My Wife's mother used to have a place in Fredericksburg, so we'd stay there and I'd ride. We plan on getting back over there sometime for the German food and riding.