My recommendation is if you want to do a BBG, work up to it and be ready to pack it in if things go wrong or just plain don't work out for you. Forcing a bad situation may be a receipt for disaster. Have a good plan in place that avoids situations that will impact you staying in the saddle with minimal breaks. If you are looking at faster speeds to get the job done, you are going at it in the wrong way IMHO. Higher speeds equals more gas stops which equals longer time. This ride is about time management, not high speed and avoiding cops.
I did mine in 23 hours and besided gas stops (<8 minutes each), we took one 45 minute break for food and a rest at 3am, the time your body most wants to sleep. Our speed was generally 5-8 mph over posted limit. That kept us just a little faster than the flow of traffic but not so much as to draw unwanted attention. Pick a route that has a posted speed of >=70 mph, few if any metro areas, straight and boring interstate, and work on minimizing your "out-of-saddle" time. If you want to make it more challenging on future rides, you can pick a tougher route but I would make your first one as easy as possible. I would also create some work-up rides that push your limits for staying awake and alert. It you find that unsafe or unobtainable, maybe your decision to back off from this goal is wise.
Organize your bike, clothing, gear, and paperwork with an eye toward not wasting time. As I tell a friend that has recently gotten the IBA bug - "Simplify, minimize, streamline". The goal of this ride is to make >1500 miles within 24 hours. It is not to have a good time, it is not to take pictures, it is not to see the sights and you are guarenteed to fail if you fiddle-fart around! Don't let anything divert time or attention to not achieving your goal. I tried to give us a buffer of at least an hour in our planning. SOMETHING will come up to eat away at your plan so if your don't build in a buffer, you will end up failing and have to start all over again.
Try to rotate gas credit card use so they don't get turned off, keep them handy so you almost have them out by the time you stop by the pump. Keep your helmet on for gas stops. Remember that anything that you take off at a stop takes away time and then you waste more time to put it back on before you can get moving again. You can even ride the planned route in advance to pick out which gas stations and pumps have reliable printers. Maximize your range by not short stopping your fuel use. If you can go 225 mile on one tank, try to pick gas stops that let you get 190-200 miles between fill ups.
I would say that the BBG was the most difficult IBA ride I have undertaken and I now know that it stretched me to my personal limit (at that point in my life). The pay off is that it returned to me a personal sense of accomplishment that surpassed most anything else in my life. If it was easy, anyone could do it and it would mean little.
P.S. My buddy and I planned extensively before attempting our first BBG and we were able to follow our plan and were successful on our first attempt. I am probably more proud of that than of the certificate!