Just go ride it and see. If you anticipate being competitive, then it gets important as to how you work the details. If you're not competitive anyway, then you have more flexibility.
My one experience doing something like this was a 12-hour time-trial (ie, non-drafting road race). The first 100 miles went great, then I just ran out of steam. I doubt there's much that I could have done differently in the way of actual performance, other than being more fit in the first place.
In my case, the course was a 26-mile loop, so I stopped each lap to refill water bottles, etc. One lesson learned is to minimize your time off the bike. If you can have a bunch of water bottles all iced down where you just grab a couple out and then keep riding, you can speed things up.
I've been using Perpetuum on some of the longer rides, and having to mix that up each lap was something else to slow me down.
If you have a crew person to take care of some of that stuff for you, it would help.
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"be careful this rando stuff is addictive and dan's the 'pusher'."