De-beading varies greatly depending on the terrain. a long slide down a muddy off camber hillside, pushing mud up the sidewall will debead almost any tire with 12 psi or less.
Straight ahead on rocky terrain one should be safe down to the 10-12 range.
If you lower your road psi from 32 to 16 you will double the surface area of the tire on the trail. That is usually enough for most guys.
Also, learn how to re-bead the tire on the trail. Good info can be found by searching this forum or post a question as a separate topic and you'll get a lot of info.
I think the wheel width means nada compared to the tire pressure as a factor in de-beading. Think about it. With the tire off the rim you can compress the sidewall with your fingers. Does it matter that the rim is compressing it another inch when a 10 inch rim is compared to an 8?
03 Rubicon; 99 xj with too much stuff to list; Unimog 406