I'd suggest looking up Fdd's threads on his outdoor grows. He has grown some monster outdoor plants. If I remember correctly he would start them inside then move them out, but I don't remember how big or anything else.
If you only plan to have 1 harvest a year then let the plant grow it will veg until aug. so thats atleast 5month of outside veg growth they will get 7, 8, 9, 10ft easy. u just better have enough nuts to make sure u have good bud & not just a plant.