IMO unless you’re going to be racing this fondo like a road race then that would be too intense of an opener. Especially if you take it all the way to the end.
I’d probably do something closer to Cajon or Laurel
The thread that @Spots mentioned is a good one for openers on the day prior to races, such as crits and road races, where there is/can be real explosiveness from the start where if you don’t get into the lead group you are dropped. I have participated in dozens of centuries and GFs over the years, both timed and untimed, and haven’t experienced that to ever be the case. As such, you should have plenty of time to get your cardio and muscular system warmed up during the actual event itself. Of course, if you want, you can bring a dumb trainer and warm up prior to it. What I’d generally recommend is an easy endurance ride the day prior and perhaps 2 days prior as well.