Vader's body

No but the celebration after the funeral was a proof😂

I dunno, we don't know the timeframe between the funeral and the celebration but I would have thought it was a few days.

Enough time for all those people who we never saw during the film to suddenly appear for a big party.

Exactly, and there must have been time to clean up the mess made by the battle, cut Jakes hair, get him a nice, smart Jedi Suit made. All that kinda stuff.

I think we have already established that Jedi do not normally disppear on their own (because if they DID than Vader would know about it), so burning them to aid this thing that does not happen is not much of an answer.