I find it effective to set cycling goals, make those goal public, and train for those goals. Because some of my cycling goals are pretty extreme by casual cyclist standards I tend to set goals for multi-year periods. For example, it took my two years of training for my transcontinental ride last summer.
Of course I didn't start by setting transcontinental goals. My first goals were around completing centuries and my first MS 150 in Memphis is 2002. My first attempt at a century was in 2001 at the Elephant Rock Ride in Castle Rock. I had never done a century and really didn't train for it. The first 30 miles of the Elephant Rock Ride is basically up hill. It crushed me. I turned off on the 65 mile loop and struggled back. My first MS 150 I averaged only about 13 mph.
To train for my first MS 150 I used the Bicycle Magazine Century Training plan which is simply a distance based training plan. It lays out how many miles per week for 10 weeks and the length of the longest ride. Very easy to do. My thinking was if I can finish a century training plan then I can do 75 miles back to back. That turns out to be true.
So my advice is to set a goal for the MS Ride. Depending upon your conditioning and cycling experience here are some suggestions:
1. Finish day 1 with as many stops as you want.
2. Finish both days with as many stops as you want.
3. Finish both days both under 6 hours.
4. Finish both days both under 5 hours.
5. Race me.
Let me know what your goal is.