One to two feet of snow still does not define the snow. If it is light powder, freshly fallen, you could do 24 inches. If it has been sitting, blowing, drifting, and developing a hard shell and a packed consistency, you won't go through 24 inches.
With the wrong, or worn, tires, you won't go through extended distances of 12 inches, particularly if you stop. Extended distances could mean anywhere from 100 feet to a mile. Keep it moving if you are in doubt as to depth or conditions.
Good performance in deep snow depends a lot on your tires and the percentage of tread left on those tires. Also, a narrow tire will tend to work better than an extremely wide tire. My 255-85 tires work pretty well.
You need experience in knowing what you can charge through and what you can't, and how to use momentum. Given the weight of the front end on these trucks, if you get it buried bad, you won't get it out without extensive shoveling or a tractor.
Very often it is important to know when NOT to stop. Have fun. We just got quite a bit of snow here, the first this winter, actually.