Firstly, I don't think C5 will drop it until it literally dies a burning death or Endemol ban them
However, if they dropped it after the current contract in 2019 I think ITV would pick up CBB (if they could/were allowed) and air it on ITV2/be. Or maybe even CBB + BBUK but for like 4 weeks each a year.
Or possibly Sky would take it and air it exactly like C5 do.... possibly even more....
Or maybe I think Endemol would take it online.
Regarding channel 4, if it got better (somehow) and ended up with growing ratings (somehow) and hit a new peak(somehow) and was then taken from Channel 5 (somehow(like bake off))
then I think C4 might consider it
