Transplant right away and allow two weeks to recover before switching to flower. I was in your same situation and it turned out successful.
Matter of fact, mine was in a 6in Terra cotta pot. I had to smash it to get the root out and when I did, the dirt came off the root and unveiled a long Taproot. It's definitely sensitive and not the easiest to work. Try to keep the root ball together instead of letting it unwind.