from what I can find out you can do it any time really. the trunk is actually lots of ariel roots. So what I have read, dig the hole where you want it to be first, make sure the area is quite damp/humid as that is important for them and not in full sun.
then lift it and replant to the same depth. Don't brush too much of the loose soil off it before replanting.

I remember seeing 2 ft sections of trunks in a garden centre many yrs ago that were not even potted up. the advice then was to dig a hole and plant the stem in a hole about 6" deep, backfill, water well and enjoy!

Thanks so much, Eileen!!! That's fab advice! I shall take all your wise words on board. Appreciate it, thanks again 👍