My first catt - how to handle a poor potting situation

[tjselwyn]

My first cattleya arrived last week, and I'm in a bit of a conundrum about it. Its two most recent growths are completely out of the pot, it's got plenty of exposed roots from older growths as well, and the potting medium is probably the worst I've ever seen - I think it's just mossy sludge. That said, the plant seems to be doing well - the canes are all fat and healthy-looking, leaves look pretty good, and it's got a spike with buds that have grown noticeably since it's arrived. So I don't think I need to panic and can wait to repot until it's got new growth and roots, but I don't really know how to manage it until then. Should I spray the exposed roots now and again to give them a bit of moisture, or should it be OK to just try and monitor the medium and water that whenever it's dried out?

For info, it's indoors with temps of 18–22C, near a west-facing window (and I'm using grow lights now that it's getting dark and dreary here in the UK). I'm not sure about humidity levels, but assuming my house is typical for the UK, probably 40–60%.