Double potting it would be the least stressful route in my opinion, but you'll probably also find yourself using a lot more water with this method... and you definitely want to safeguard yourself against excess soil moisture in the later stages of flowering. Soggy soil conditions can lead to root-rot and bud rot in pretty short order. When the soil/root mass is dry and can be easily lifted out of the pot, transplanting into the slightly larger container can be relatively pain-free if things if preparations are made in advance and the transition is gentle. Take the path of least resistance and do what's most comfortable for you.

And thanks for the intended rep, I'm glad I've been able to help out. Enjoy the harvest when that time finally comes! :thumbsup: