Further to my comment earlier I've amended the haunted hut scenerio a bit.
When Luke lands, after completing his training on Dagobah, Threepio, who has been left with the Falcon, says something along the lines of , "Master Luke, I tried to stop them...."
To which he says something like "Oh no...Leia!". (I'm sure something along those lines can be sampled from other sources).
The Hut scene plays out in the evening as he has been planning his rescue plan for the rescue plan that's already gone wrong (he doubts if he can rescue them all alone now Leia has messed up the plan) and Ben turns up to deliver a bit of information which explains Leia's lack of patience....
This version would have to play now after Leia has been captured and Threepio wouldn't be able to warn Luke about the trapdoor because he hasn't seen it yet.
The basic idea may be a workable way of restoring certain elements of this lost scene :
