I would do the bit you do first in the dark, when you’re fresher and are riding harder. Once you’re exhausted and going slow you’re more likely to get cold at night (even in summer). Plus, riding in the daylight, it is easier to keep your spirits up when you get overwhelmingly tired, at night it all seems harder!
If there’s one bit you know the navigation, I’d do that in the night and leave the harder navigation to daylight riding. Even simple navigation can be hard once you’re exhausted and it’s pretty hard to keep concentrating for the whole 202miles so simple nagivation mistakes do happen, particularly at night. Mike Cotty took a wrong turn on the section of trail that was almost closest to his home in the night on his last SDD!
Good luck! :-)