Good advice so far, thanks everyone! Seems like riding lots, and far, though not as far as the actual event, is the current concensus. Can’t say that doesn’t make sense! Riding on the edge of bonk is a great idea too. Ounce of prevention, and all that.
I’ve done the same event here in Finland once before, 7-8 years ago, so I know I can do it, even with minimal preparation (just like last time!). Completion is not a problem in other words.
Goal this time is to try for a significantly better time, under 4 hours. Last time I did a 4:45. Most of my usual rides these days are of the 1hour to 1hour30 variety, or sessioning local downhill spots, with nice chat breaks in between. Very different to a 60km trek…