Some basic info first...
Phase 1: ST 4 & 5 days a week (35-55 minutes each)
Phase 2 & 3: ST 6 days a week (55-90 minutes) PLUS Cardio 4 times a week (30 min)
Depending on how much TIME you have once you get to the gym, may be a factor.
Double up workouts. If you're only used to working out 45 minutes or less, probably not for you. ST+Cardio days in Phase 2 & 3 can take 2 hours.
Stretch the program out 20-24 weeks, breaking each "week" into 2 weeks
A combination of above, which I'd recommend over the other two if you think you can pull it off.
Double up workouts as necessary in Phase 1 (NOT on Legs days) keeping it to 4 weeks. These are shorter WO (workout) days, so I think its possible depending on your endurance. This is the muscle BUILDING phase, so I think stretching it out isn't as good an idea.
Phase 2 and 3-- break the weeks into 2 weeks, always including a Legs WO each week.
The program will take you 20 weeks total with option 3, but I bet you still get good results IF you stick to clean eating.
Other factors- do you have a home gym/equipment ? do you like to do cardio outside?
I hope this helps with your decision. Let us know how it goes!