Leeds fans celebrating promotion

The transcript contains a brief statement indicating the speaker is leaving.

What do you think the speaker means by 'I'm off'?

In what context might someone say 'I'm off'?

How does the phrase 'I'm off' reflect the speaker's mood or intention?

What are some possible reactions to someone saying 'I'm off'?

Can you think of a situation where saying 'I'm off' would be inappropriate? Why?