Help with Grammatophyllum!!!

[GinaStarSeed]

Help please! My very favorite orchid,my Grammatophyllum is struggling. It has been doing wonderfully for almost a year. Due to not repotting it soon enough and it getting very underwatered/low humidity the last few weeks all of her leaves are turning yellow. I have gotten the humidity back up and gotten her water. And I plan to repot her as soon as she seems less stressed. My question is, one all the leaves are yellowing like this, is there any bouncing back? Can the leaves turn green again? Will they still continue to yellow and fall off?? I am so bummed about this... here are some photos. The leaves look a lot more green in these photos than they actually are.. they are very yellow.. any advice appreciated. I love this orchid.