I will preface this by saying that I am making some assumptions on different readings of the kanji. I never really thought of this term as "ten minutes" when used in the metaphoric sense as "enough," for the obvious reason that the pronunciation is different, but maybe there is an actual correlation that I am unaware of.
"Ten minutes" is pronounced じっぷん or じゅっぷん.
"Satisfactory" or "enough" is pronounced じゅうぶん.
十二分= More than enough
十分= Plenty; enough; sufficient; satisfactory; adequate;
In a counting system based on intervals of ten, the number ten will represent a complete set. 分 can be thought of as "degree," as well as minute (it has many meanings). Thus a "complete degree" of something will be "enough". This expression can be seen as arbitrary in as much as an english speaker will use "100%" as an arbitrary term to mean "giving it one's all," or will say "That girl is a ten" to mean a stunning beauty.