In a comment on Facebook of my XXXXXXL-Snake post (https://www.thingiverse.com/thing:3632627), a guy commented with: "but there goes more! ;)", so I said "challenge accepted" :-)
The length is now 250cm.
It is optimized for the bed of a Prusa i3 MK2/3S (size 250mmx210mm) and the tail is children-friendly with a round end.