The other thing you would want to take into account (besides the distance) is the amount of climbing on the course. Both Jefferson and Montebello are probably the two most challenging on the course. It doesn't look like the route takes you to the top of Montebello but to the Picchetti Winery. But both of these climbs have fairly steep sections and for someone new to road biking could be fairly challenging. I would recommend trying to ride these climbs before hand as to get a feel for what to expect.