I used to be a lifeguard in SoCal, at the time we had mainly Nissan Pathfinders and Nissan Hardbodies. In those, we had wider tires and would deflate then a bit to run on the sand. It worked great.
We did however have a Chevy 3500 dually with stock tires. It would tend to be harder to get through the sand as the tires were skinnier and it wouldn't "float" as well on the sand. I think that if you could get larger on the fronts, it would be okay on the sand. I realize that you can't go much larger on the rears without tire rub and heat build up unless you space the rims out.
We did however have a Chevy 3500 dually with stock tires. It would tend to be harder to get through the sand as the tires were skinnier and it wouldn't "float" as well on the sand. I think that if you could get larger on the fronts, it would be okay on the sand. I realize that you can't go much larger on the rears without tire rub and heat build up unless you space the rims out.