Traveling late in pregnancy

I am due October 3rd, and my SIL is due September 4th. We were hoping to go visit her once her baby is born, before ours is here. However, they live six hours (driving) away. Originally, I had thought it would be fine, but now realizing I will be 36 weeks (if her baby comes on time, which with it being her first is unlikely) I am a bit more hesitant. I was a day early with my first, and I am not high risk. There are great hospitals around the entire drive, in case something happened, and while not ideal, it wouldn’t be the end of the world to me to end up delivering at a random location. I haven’t discussed this with my dr yet, so he may say flat out no, but curious if others have traveled that late in pregnancy?