Sounds like a good idea to me. I occasionally participate in a similar monthly contest; it is my experience that a month is rather short, especially for us analog people (the one I participate in is mainly populated by "the others", and just a few analog shooters). Two weeks to think of a good scene in the back of your mind, third weekend to shoot & develop, skip printing, scan from negative.
Take 1 1/2 month, and there's more time to shoot again and to do proper printing (I find scanning a print a lot easier than scanning from the negative).
Long story short: yes, I'd be interested in such a contest.