Should I continue, or are group books (even large, diverse groups) over and done with?

I don't think that "group" novels are cliche, if done well. However, I think you do need to be concerned about confusion - I've read a lot of books of this kind where I can't keep the characters straight or remember what name goes with one plot line. If there is a lot of character development (and unique names don't hurt), I think you could be successful with this. Instead of featuring a character per day, why not each character per week (or even month?) That might be less confusing and give more continuity.