I had started air-layer on a 7-ft tall single trunk fig plant at mid-height to make two out of it (wind was always toppling it). There are plenty of roots for a number of weeks now but I decided no to separate the two now but store it in a cellar as is, and separate the air-layered branch in spring. This will save me space of one more pot in the limited space in cold storage in the basement.

Any downside to this idea of postponing the separation of air-layered branch until spring such as any kind of damage to the new roots?

Will it be better in the spring to separate when still dormant or when the plant start waking up?