You could, as Jerry suggested, get down-n-dirty. You can carry a small section of painter's tarp to avoid the dirty bit. It's always best to use your eyes when taking a picture.
If you're unable assume the prone position, the next suggestion would be to get long glass, and stand quite a bit away. This minimizes the angle of perspective, and can yield nice results. Maybe in this situation you could get down on one knee and shoot, and get good results.
If you're committed to shooting blindly, I'd start by practicing doing so, and I'd mount a speedlite, AF-S mode, assisted focus, and shoot in the evening so that you can see the assistance light from the flash hitting your target. Observe the angle of the camera to the target, how wide you have to go, yada yada. The eliminate the speedlite, and practice some more. Ultimately, I'd try AF-C 9 point, and see how that does.