Actually, as long as the ground is solid under you, the X will do just fine with that amount of snow. Out here I don't have to put the X in 4wd with only 3-5 inches and I do not deflate my stock tires from 35 psi. Of course we have Champange Powder and 4wd might be required if you have snow more like Sierra Cement. My first instinct would be to try driving in 2wd and only put it in 4wd if you start having problems. IMO, it is best to do everything you can in 2wd that way if you do get stuck, then you still have 4wd to get you out. I do put it in 4wd if I must have the extra control. Have fun...
Kurt