Guess I should order my new smart pots then...lolAs per @mephisto. You can transplant their girls just when they shoe their sex. @Rhyce Saroni does it all the time. Look into it and you'll have the time to still bring the new girls to maturity in larger containers.
I've transplanted before from crap soil to better soil and never had any issues so not too worried about that. One of the girls in my current grow was transplanted after about 8 days of no growth and now she's almost as big as the others...