Leftovers don't normally burn very well or smell very good if you try so the goal is always no leftovers unless something will keep. If not there's always the communal leftover pile:
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That brown thing on top is a slab o bacon. Yellow is three pounds of butter. Must have been there for a week or three before we got there....

My wife and I were squatters at that site for probably three nights (hey it was our honeymoon) with no bear sightings so it must be a better plan than burning right? Hey, we didn't have a problem....

What you do is up to you but what you experience may be, in large part, up to luck and those who used a site before you.