I have got PR approval email on September 26th, replied on September 27th and got portal credentials with username and temporary password on October 6th. It varies. Some got very next day in September.
I think, once you have valid work permit and valid visa, you can enter Canada. If you are on maintained status, you should not leave to keep the current status. If you get eCoPR by that time, then you need to apply for PRTD...