The sync from scratch was going well with about 15% a day,
Thanks,"15% a day" speaks volumes.
My gained experience evidences that IBD involving 16 Gb RAM machine and external SSD (870 EVO Samsung) goes much faster. 4 weeks ago it took less than 36 hours to download full blockchain from the scratch. The properly tuned bincoin.conf (dbcache=1/4 RAM and blocksonly=1) facilitates IBD.