There's a german guy who has experimented with Rodinal in cold temperatures, I just cannot find his website at the moment. Basically his findings are positive as far as I can remember. Compared to 20C you calculate your time x 1.3 for two degrees and x 1.6 for four degrees lower temperature. This is for a normal agitation method.

For stand development I think 14C is all right. I would whirl the tank every 30min though.