I think my medium is suboptimal

[Highland Fashionista]

Hi everyone. I'm new here and new to orchids as well. I recently acquired 2 Phals after suffering a rather spectacular bit of "Phal Fail" recently. Totally my fault. So to avoid making the same mistakes again, I was wondering if I could get some pointers please.

I currently have two plants. Plant one was a gift, and when I got it home I repotted it (despite it being in bloom), as it looked like it had a degree of root rot. I was not wrong. I took away the old medium and snipped all of the roots that were brown and mushy, hollow, or black and put cinnamon on the cut ends. Many had roots that continued beyond where I had cut that were still green, but I am of the understanding that the rot has to go. I kept everything that felt turgid. Many roots appeared yellow but they were still turgid. Repotted in the only mix I had available, which is Westlands orchid mix that you can get at Homebase (like Home Depot only in the UK). I realise now that this medium is probably too fine and dense for my Phals. There seems to be a lot of soil in it, and it holds a lot of water. I live in Scotland, and we only have light about 7 hours a day during winter. I fear I may be dooming these poor Phals in this medium with such low light and potential for cool conditions. I have not watered since I repotted, nor do I intend to for a long, long time. Some of the roots on plant 1 actually look better today. But do I dare try to repot again once I get some better medium?

Here are some pics. I am less worried about plant 2 (the darker one) than plant 1. Sorry, I didn't have the foresight to take snaps while I was repotting, so you can only see the top bits of root.