I've never used ibuprofen, or any pain killer. I have used Savlon, which works best for me. Use it before you get sore, not after and wash regularly, at least every day with soap. Then clean shorts. You shouldn't get saddle sore if you do that.
Caffeine is fair enough. But getting plenty of sleep before the ride is a hell of a lot better.
Carry some cafeine pills or dark chocolate. But try not to use it unless you need to. You shouldn't need it on the first night. If you do then I hope you can pedal fast and make time up for sleep or some very slow grovelling.