Intentions aside, 6 hours is a long time to ride by yourself. Well done!
I don't think I'd classify the SIUE trails as "easy" in the context of epic riding. Easy to once, perhaps, but they have so many little obstacles you're never able to just relax and ride. Four laps around Berryman, with it's long, fast sections punctuated by significant technical and physical efforts would probably be no harder. Anyway, agree with Bill, six hours is about as far as I ever went solo, even back in the day of 700-mile weeks (on road, of course, cuz that's the only riding I was ever any good at).
Neat idea! I admire your effort and the goal, that is pretty cool. I also admire your ability to start riding at 7 am in under 30 degree weather, I am too spoiled down here now, that sounds scary to me, haha. :)
Weirdly, I feel way more beat up from that ride than I did from BT Epic. Not sure what that's all about, but you guys' comments add some good perspective for me.