I would pot it up immediately. You don't want to let the new roots get any longer. I generally pot as soon as I see the location of the new growth, so I can judge the best orientation for the next year's growth. The new roots are VERY brittle and it is hard to work with them, so be cautious. However, if one is damaged, more will grow, so just do your best. The happy sap is fine. The plant is still a good bit before watering. See this post to judge when to start with the water.
Catasetinae Notes from Sunset Valley Orchids