There are many ultra’s to choose from, but these will definitely be intermediate goals, to get to the 100 Miler.
This one looks promising, and a nice excuse to visit Texel:
Zestig van Texel
60 or 120 K race, April 5 2021 with a grueling 30K in beach sand. Looking forward.
To get familiar with my goal terrain and weather conditions:
Bello Gallico
So 1 year before the 100 Miler, I will try to run the 50 Miler of the same event. December 2020
Not sure yet what other races will lay ahead, but follow my blog, and we both will find out.