I have a 12x16 garage....and questions.

The goal is a perpetual grow with at least 1 VEG and 2 FLOWER spaces. The one car garage is attached to my two car garage at the rear of the garage. I have gas heat in this one car garage but no A/C.
1. Should I frame in a small room? Maybe 8x8? I have a single hose A/C unit that I could vent to the outside. I could put a veg tent outside of the room during the winter when the garage door might not be of use.
OR
2. Do I use the entire garage for a grow and use the tent as a VEG station with the zippers taped up to prevent light leaks to the flowering stations?

My issues are this.....I have 3 young kids. If I frame the room they could still use the garage during the spring/summer if need be. Also, I only provide meds to my wife, a patient and myself. I fell that if I turn the entire garage into a grow I should consider getting more patients and I don't know if I want that.

Any suggestion or ideas would be great.

How much medicine do you want to grow? What medium would you prefer to use? There are so many options and combination of options. You should really examine those two questions first. Then look at the best solutions for enviornment. Even though your enviornment is the most import aspect of your grow there are many different options when it comes to equipment you don't want to underestimate or overestimate any of you're needs.
I would personally use that space and build 2 rooms inside of the garage. A small veg and then a nice flower room. 4x16 and 8x16. You could use 600's and scrog method. The 600s will help reduce heat and the scrog will increase your yields. But that's just my preferred method. Whatever you do plan and plan it out again. Good luck.