Fuel wise, it rally depends on driving habits off road. If you're gassing it over every obsticle, of course you're going to burn it off a LOT faster vs. if you follow the old "slow is smooth, and smooth is fast" rule. Not to mention you'll be a lot less likely to brake something taking it nice and slow.
It also depends on exactly how much driving you're planning on doing each day. Only going a few miles could take you a ferw hours depending on how dificult the trails are.
Long and short, your fuel consumption depends on you. Were it me, I'd probably ration my fuel consumption and set a limit for driving each day to how much fuel is used. In doing so, you could get what you are looking for (video), manage to stay out for an extended period of time, and still have fuel left over. Save the resurve for emergencies.