I am planning on a 200k brevet on October 16. What is a realistic mileage base to reach before then? I have hopes of getting to 110 by early October, am currently at 60 - next weekend hope to reach at least 66-68. Considering my speed (average about 13 right now), does my base really need to exceed 100 before the event?

My thought is that it would be good if possible, at least, once. I figure it would be helpful for my body to know what it feels like to spend that many hours in the saddle. Is it necessary though? I don't want to set myself up for a DNF because my base isn't high enough, but I want to have realistic training goals as well.