TLDR: be prepared to spend 3 to 5hrs. on the course.
It's worth taking a look at the times from the last ultralong at Fishtrap before Sunday's goat, as they have similar overall stats (sans skip):
2022 Goat: 28 controls / 18.6km / 475m
2019: 28 controls / 18.1km / 430mhttp://obasen.orientering.se/winsplits/online/en/d...
It was quite hot that year, hot enough to slow people down, so if you’re fast maybe 2hrs is doable?
I'm excited for it :)