the visa expires on Jan10. The work permit is valid until mid next year. So have the letter from the employer stating the last day of work which matches the expiry of the visa. That sounds like the easiest way
how can you do it in advance if you have to cancel WP and visa the same day? I have actually heard of quite a few people receiving the 7 days “grace” to leave. Going to labor office, followed by immigration, followed by the airport in a single day? I don’t think so!!