Good advice so far. Slow and 4 Low are generally good. Checking the depth and the bottom is also good. I've crossed a lot of rivers in Colorado, but they have all had good gravel bottoms, good traction. Been in water about a third up my door (old 88 Toyota pickup), probably 3 ft. or so.

If you submerge your wheel bearings, they will need maintenance, as in re-packing. I don't know if that SUV has sealed bearings or not. If so, then it might be a problem. Some other areas that don't like to get dunked are your front and rear differentials, transmission, and transfer case. I routed all the breathers on mine waaaay up so that they wouldn't suck in water. If you get water in any of those, it needs to come out and quickly. One way to do that is to stop for an hour or so, let the water settle to the bottom, and crack the drain plug, but tighten it back up when oil starts coming out - remember water is heavier than oil. It will still need a fluid change soon, though.

If your door seals are bad, find out where the computer is. Usually, there is at least one in the passenger footwell. If that gets wet, it's quite expensive.

Don't let the vehicle stall in the water if the tailpipe is submerged. Water can create enough back pressure to prevent starting, or make it very hard.

Your frame rails are the parts of the frame that run from bumper to bumper. They are lower than the door.

Basically, if you submerge it, it needs fluids changed, bearings and driveshafts repacked. If water gets in, rust soon follows, and that's real trouble.

I put over 280,000 miles on my Toyota with LOTS of off-roading and water crossings, no problem, but I am anal about the maintenance also.