As others have said, know what others are driving on the sand you plan to encounter. If you only see dune buggies I would stay off. If you see similar rigs like yours or bigger than you have a chance. Before you venture out, ask someone else how low they go. Haven't met a single person that ventures into areas with great chance of getting stuck be non-friendly as you may be there only hope of getting out. That will give you a good starting point.
If you do venture out, as soon as you lose forward momentum, STOP. Spinning the tires will quickly just bury you deeper. Lower the pressure some more, take the time to do some digging.
Lastly, check youtube for the place you are going. Most places where folks get stuck often have a lot of videos posted up.