I've done two BBGs. The first I finished with only a few minutes to spare as a result of major fatigue setting in between 2AM and 4AM in the morning (I started at 6AM). On the second attempt, I started at 8PM and I hit 1500 miles before 6PM the next day. I'm not sure if it's better to leave at night, 4AM in the morning is still really difficult, but finishing during the day is better than finishing in the wee hours of the morning. I was hoping to get some sleep before leaving at 10PM but couldn't sleep and left at 8PM instead. Next time I may try leaving at midnight.
The second time, I planned my route to avoid traffic, construction, driving into the sun, and non-interstate roads. I set a 10 minute timer on my watch each time I stopped and was on the road again before it expired on most stops. I didn't take my helmet off at stops. Stops were for gas, recording my receipts, and bathroom breaks only. I still made mistakes. I planned my gas stops and then decided on the ride to try to stretch as far as I could on each tank, resulting in a detour in Oklahoma to find a gas station. I snacked (nuts and dried fruit) from supplies in my tank bag while riding and drank from a hydration bladder also in the tank bag. I used InRoute app on my iphone to plan my route and loaded a GPX file of my route into my nav system as a backup. I used the SWConnect app to map my progress and upload pictures of my receipts to the cloud and also took a picture of every receipt on my phone. I listen to Audible books while riding, but switched to rock and roll for a few hours at 3AM to help with fatigue. Here is the Spotwalla trace of my trip. I started in St. Louis.
https://spotwalla.com/tripViewer.php?id=1fd175d5ef8833eaa4