The best thing you can do is to take 3 more days off. Sleep as much as you can, sit in the sun for a bit to get some Vitamin D and take some Vitamin C and Zinc. I don't recommend even easy rides when you have chills. Easy rides will prolong your illness and do nothing for your fitness.
On Monday if you feel healthy get back on plan and repeat week #12.
Getting healthy is priority #1. The Breck 100 course is too hard to finish if you are less than 100% healthy due to the altitude, elevation gain and general toughness of the terrain.
Lynda