I have a peyote cluster that is in a pot that is clearly too small for her. There is no room for root expansion and I doubt it'll grow any further in this state. Over winter she lost a lot of water and I decided to water her last friday as she appeared in pretty bad shape. In just two days she went from looking badly dehydrated to a very healthy state.

I want to repot her, but I'm unsure if I can repot her just two days after watering. The clump of soil that's being kept together around her roots is almost fully dry again and I have a larger pot and cactus soil. How long should I wait before repotting or can I just take her out and move her to a larger pot already? I'm aware I shouldn't water her for 6 weeks after repotting or root rot might kill the entire plant.

I'd go ahead and re-pot now
how big of a pot are you going up to? i'd recommend 1-2" larger max