howdy!
not having grown bellina i can only offer our experience with a violacea indigo that we overwintered for a friend.
it came in full moss, the type typical of nursery orchids. we watered it when the top felt crispy, as per general guidelines. it is in one of those soft plastic trade pots, i think an 8cm one. but it got pretty cold here over the winter and the plant went into dormancy basically. it has yet to start growing a new leaf
hopefully we did not set this plant back too much for our friend.
the roots look good, and it certainly isn't dead, but it is not vigorous, that's for sure. probably needed to keep it over the near 55 temps on winter nights that we had this year....but it did at least survive those temps in full moss