I am actually doing a test right now, can post pics tomorrow if you like, with 5-6 plants. They are all outdoors the temps are around 35-68F. Very low at night around 36-50F (and everybody thinks California gets nice winters HAHAH... yeah right..., well I guess compared to Alaska or Chicago then yeah we do). Well what I am trying to see is if I can get some extra bud outside in the winter while my indoor crop is being harvested every month. Here is the problem I ran into, most of the indica dominant plants are refusing to flower and are actually just slowly vegging. This happens because everyday the days are getting longer by about 30-40 seconds which screws with the plants (my theory). Now I have a few indica doms flowering and a lot of the sativas are flowering. The part I love is the beautiful purple buds that are developing (probably the blackberry coming out of hiding). I am probably guessing I will get 20-30grams per plant, which is good because it is an addition to what I get indoors. the bad part is mold mold mold. Got to keep an eye out for that crap!
I vegged 4 indoors for 3 weeks then stuck it outside and then during that vegging time I had one outside vegging, which that one is tall and lanky.
Depends where you live, no one is really trying to bust someone with a few plants... I would go with the out in the open place. I have LAPD helicopter flying over my house once a day in the summer when I am growing outdoors, I just wave at them... Although I do have a card, but no one has ever came knocking on my door... It might be different in a state that has a zero tolerance marijuana policy. Go on your computer and google what the punishment for having the amount of plants you are going to have in your state is. (not the federal punishment, that is a felony per plant I believe, which applies to me and you and everyone else) After you get your answer from Google, decide whether you want to risk it or not. I mean I had about 15 plants sitting in the open summer of 2012, large ones too and my recommendation on allows for 6 plants... Once again, no one came knocking on my door. Sooo I say do it, but its up to you.