jd3x,
I feel certain the result would have been the same regardless of the tires (unless they were about 2-3x taller). I was in gear A-1. As soon as I felt the rear wheel start to sink, I immediately stopped the tractor and lifted the bush hog to its highest level. All this did was allow the rear wheel to sink further and the bush hog stayed on ground level.
Within a couple seconds, the frame was on the ground. Then, I tried to use the FEL to walk backwards. All this did was cause me to slide sideways into the ditch and allow the front tire to sink
A 4wd truck tried to pull me forward, but the tractor wouldn't budge! 
I feel certain the result would have been the same regardless of the tires (unless they were about 2-3x taller). I was in gear A-1. As soon as I felt the rear wheel start to sink, I immediately stopped the tractor and lifted the bush hog to its highest level. All this did was allow the rear wheel to sink further and the bush hog stayed on ground level.