Applying for a visitor status extension gives you implied status until they make a decision (I stand to be corrected by more senior forum members). My partner has had 2 extensions (been here since September 2017). The first one was processed within a month, but the second took about three months. We applied September 9, 2018 as his status ended on September 29, 2018. He received the notice of extension just prior to Christmas.
Whenever we've submitted a request for extension, we've included letters from both of us saying that he will be supported by a combination of his savings and my savings, and that if the extension is refused, he will leave the country. We've also noted that we recognize that he can't work in the country as a visitor, and we included bank statements to show that we have funds available. We addressed how expenses (transportation, housing, etc) will be covered. Both times we were also upfront about the fact that we were applying for PR - the first time, we said we wanted to be able to fulfill the 1 year cohabitation requirement for common-law, and the second time we said that we were just getting our documents ready but needed the extension so as to have time to send them.
