The distances covered in last year's OMM were as follows (taken from the teams' RouteGadget plots):
Elite 78.3 km
A 69.8 km
B 59.6 km
C 47.0 km
LS 72.5 km
MS 61.4 km
SS 44.8 km
Height gain needs to be taken into account also - I've only looked at day 1 winners by contour counting so not very accurate: Elite did the most, closely followed by LS, then A, B and MS who all did similar amounts, then C. I haven't measured the height gain of SS.