Leaf & Root Issues - Mini Phal - Newbie

[Higgins23]

Hi there,
I'm an orchid newbie and I have SO many questions about my phals! I'll separate them out into relevant posts, however. I'm most concerned about one of the mini phals. I'm attaching pictures. I've had this one for about 6 or 7 months. It's a grocery store rescue. It was in full bloom when I brought it home. It's been repotted once and I cleaned up the roots quite a bit as they were a rotted mess! Now, months later, it's not doing so well The leaves are drooping and puckered. I researched and thought it was dehydration, but now I'm not so sure about that. There are barely any roots left, BUT - you'll see in one of the pictures I've attached that there is a new leaf coming as well as a new root (I think)! She's sitting with her buddy on a hydration tray I made when I thought she wasn't getting enough moisture when we started running our heat in the house. Questions:
1. Is her pot too big for her root system?
2. Should she be in a different medium?
3. What should I do to help her get better?
Thank you!!