Calathea obsession continues: should I repot this now, or wait? With photos

[CarterBeatsTheDevil]

The one leaf is a bit yellow because it was previously disastrously over watered. I've been drying it out on the advice of wise posters here. But it does also seem very potbound. Should I repot it now or wait until next spring?

I would. Can you use rainwater instead of tap water too?

Probably. I was also thinking about buying some stuff I saw advertised that you can add to water to make it nicer for plants.

Yes, but don't go too much bigger. Next pot size up is good.