What a way to end the year. We'll pray that things get better for you all, especially your BIL.
I have a similar travel story during that same time. We live in Murrieta, right down the road from Hemet. We retired from Anaheim, right next to Fullerton, and my BIL just retired to Reno (specifically Spanish Springs next to Sparks) in October and we're going to go visit him later this month.
During the days you describe another BIL who lives in Riverside drove to Sparks to visit the other BIL. They spent a few days including New Years Eve in Reno. On Monday, both BILs caravaned back down to my house to bring down some extra furniture they were donating to other relatives. That is quite a drive and they were tired when they arrived too. On Tuesday, I delivered the furniture. I can sure relate to the distances, roads and towns traveled.
I hope your BIL continues to improve. As you've shown it's important to be able to help family. Happy Birthday to your daughter. My daughter's birthday was on December 26th. This is weird that everything is so simlar.