Yes, must be earliest, and by far. Locals noted that near Dudinka, ice breakup in 2020 was May 16th, close to midnight local time, thus breaking previous record (1997, May 21st) by 5 days. In 2019, solid river ice was still present for some 1100 km distance from the place, for May 16th. They also note that Yenisei ice this year is unusually thin, too.