I don't get how you figure it's small? There's easily enough trail miles to take up more time than we're going to have, so long as one actually knows where to look. I think a lot of people make the mistake of dropping anchor in the big campground area and then just taking some of the trails that spur off from there, instead of digging a little deeper. If we went there, we'd run out of gas and time quite a bit before running out of terrain.
When I took Opferman there, I made a few mistakes. First, I had us camp quite a ways out, which was out of habit more than anything else, because we also ride desert roads off in the other direction so it's more flexible, but it's not an ideal spot to ride McCubbins from. If we went there, I'd have us camp at one of the spots within walking distance from a trailhead. I also ended up routing us over a lot of gravel roads because I wanted to explore one particular trail that just happened to be on the other side of the planet from where we parked. That resulted in a lot of boring riding and a lot of gas spent "commuting." If we went again, I think I could do a lot better on that angle, keeping us about 95% in the trail network.