’I’m off’ doesn’t mean you’re not in a working order. This expression is often used when leaving and it actually means ’I’m leaving’. If you would like to say where you’re heading, you can do so by adding ’to’ and your destination.
– Bye! I’m off to work.
– I must be off now. See you later!
– It’s getting very late. I’m off to bed.
– Take care! I’m off to the beach.
