Schedule it once. Forget it.

Mailbox forwarding is set exactly as in the M365 admin centre. It is switched on by the hourly runner on the start date and removed the day after the last day; any forwarding that was already set is put back.

Added to the named location by the hourly runner on the start date and removed the day after the last day. If the country was already in the location it is left alone. Conditional Access can take a few minutes to pick up the change.

The out-of-office reply is switched on by the hourly runner on the start date (or the next matching day, for a weekly schedule) and removed the day after the last day; any reply that was already set is restored.