DR350 Sprocket Ratio

I do most of my riding off-road and I have found that my 1998 DR350 SE is geared too high for the type of riding I do. I need more low-end low-speed punch for when I'm picking my way through ruts and crevices. I was thinking of upsizing my rear sprocket as opposed to downsizing the front. I believe this is an easier modification and also places less stress on the chain. Of course, my chain will then be too short. Any comments on any of this ?

Note: I have an O-ring chain if this makes any difference.