Long time since I did l/h down the back, and at my age I/we wouldn’t consider ever doing it!
We have a fairly simple LHR-IAD (after a UK night-stop) in a week or so, and the one thing always in my mind is that I then have to navigate the Washington Beltway etc. for about 45 minutes. I know the area and the roads well (or 23rd visit), but that doesn’t stop the Beltway being manic. Being rested and alert is critical to my thinking.