Good luck!

Not done it but I once did something similar with time trials and, based on that experience, if I were to do it, I'd try to do the shortest distances first. Logic being that after a 200 or even a 300, a rider in decent shape will feel ok to ride again after a day or so. A 400 needs a little bit more recovery and a 600 a bit more still. So, say I started with a 200 on a Saturday and a 300 on the Monday, a 400 should be ok on the Wenesday, then 2 days off before a 600 at the weekend, and the recovery from that would be outside the 7 days.