Root problems

Rookie mistake. I have a king Louie female that during veg exploded with nice growth. Very bushy and all around really healthy. She started to preflower around week 5 and I got a little to excited and around week 8 put her in the flowering tent. Which within 3 days started showing white hairs. However, I didn’t even think about transplanting her out of the one gallon pot. She’s now in day 11 of flower. All the bud sites still look healthy and pushing out lots of white hairs daily. The lowest quarter of the plant is dropping. Looking very sick and some of the leaves have died off. I know that I’m extremely root bound right now. I even had a brand new 5 gallon pot in the storage to transplant before flower. Do you think if I’m extremely careful that I could get away with the transplant without affecting too much of the yield? Do you think it’ll just die at this point? She just doesn’t look good at all.

I can and will post pictures later today when they wake up. Thanks for any replies and/or help!

I’d up-pot into a 2-3 gallon pot.

First two kind of show how they have been. Last night I decided to try something. Instead of removing the entire plant. I cut most of the old 1 gallon container off. Exposing nearing 95% of the roots. I then carefully massaged the soil and roots until the soil loosened up. Once most of the roots were loosened as well. I put the remaining container with roots and all into the 5 gallon bucket and watered her. I then took a side shoot and tied it down slightly to where the bud site wasn’t facing completely up. Doing this I hoped it would try to point back toward the lights meaning that she is still alive and thriving. I put them to sleep last night expecting the worst. I checked on them as soon as they woke up. She grew nearly a half inch in 12 hours and the side shoot was pointing straight up at the light. As of right now she appears to be happy with her new home. I’ll post pictures and updates from here until harvest.