Maybe the 84h morning start could actually be easier, with (almost) four full days and only three nights until the cutoff time. If you are fast enough on the road that should require relatively little night riding and a very normal sleep schedule, as opposed to messing up your rhythm by riding through the first night after the 90h start.
84h minus 3x9h for the nights would require an effective average of about 21.5 km/h (including all daytime stops). Not easy, but possible with efficient stops.
The other critical issue is to accumulate enough time in the bank before the two evenings, so that sleeping does not get you behind the cutoff times of the morning controls.
Last edited by siebengang; 12-10-21 at 02:03 PM.