seems like a waste. if you have room for a larger container then why not start off with it rather than stressing the plant with an unnecessary transplant.
no matter the growing media or irrigation technique i have always made every effort to avoid transplanting, especially right before flowering. my clones go straight into the container that they will eventually be harvested from. but that's just me.....
do you have a soil recipe that you are completely committed to or have used eextensively? are you avoiding chemical nutes for flavor or other reasons? are you testing your soil for nutrient levels?
the reason i asked if you were using liquid nutes is because they will give you more precise control over a plants health as opposed to ammending your soil which can be an indeterminate process that is harder to correct.
i have no doubt you could grow this way but i think that what we all strive for is control and efficiency in our grows. eliminating assumptions and unknown variables can only help the final yield.
i am not trying to take the wind out of your sails or deter you from doing it, i am just trying to make sense of it, that's all. i spend a lot of time trying to make sense out things these days it seems.
i wish you the best with your grow however you choose to approach it but definitely keep us all posted.
peace.