Ducati7,
Some of us are not so lucky and have been stuck at Glamis, Gordons Well, and Butter Cup. First off, I don't know if you've been there before but, the smart move would be to try and arrive in the daytime, and, try and camp in an area, if possible, where there are not too many "crazies" lurking around. Lots of folks go to the areas just south of the Glamis Store. There are quite a few sort of "Cul-de-sacs" that you can roam around in and still be in fairly stable ground.
But, this is only if you don't have a camp destination already picked out. If you do, as in down Geckco Road or the like, then, there's a fair possibility you could get stuck. Getting any motor home stuck in the sand is a pain, getting a Diesel pusher is even worse. I've been stuck quite a few times in my earlier years. I even let the pressure down in my tires which helped quite a bit.
I wouldn't even think about doing that today. Come to think of it, I won't even go NEAR Glamis anymore with the exception of driving through it to get to eastern destinations. Waaaaaay tooo many idiots out there for me and the wife. Anyway, as far as attaching your tow straps to your coach, there's no need to call the manufacture. This is academic. Simply look under the front end, and find structural components that withstand the stress of the pull. I've seen folks tie around the straight front axle and, it worked but, not too keen on that. It may be all you can get to.
The one thing that's drastically important is to assume the path of the tow strap and, in that, make sure it does NOT DO ANY DAMAGE TO the body. I pretty much assume you already know that.
The plywood strips, while fragile and will splinter rather quickly, have worked for us several times over. The Carpet runners sound like a neat trick too. Good luck.
Scott