I agree with the advice Canadianwoman gave. I don't think the timing is a big problem in itself. There are cases of people who get married just before one of them is removed from Canada. The focus in these cases is clearly the genuineness of the relationship, not the timing of the marriage in and of itself. The timing is a problem if the courtship has been been short.
The fact that you didn't have an interview doesn't mean they didn't think your relationship was genuine, in the sense that a sham marriage would not be genuine because it involves bad faith. It probably means that they didn't think you had serious enough reasons for not living together or getting married already, so you didn't meet the definition of "conjugal partners." It would be perverse to now blame you for getting married.
For example, if two people are a genuine couple and apply as common-law partners, but are determined to have cohabited for only eleven months instead of twelve, they will be turned down. The lack of a continuous one-year period of cohabitation is unlikely to be held against them if they get married later on and apply that way. Meeting the criteria and being in good faith are two separate questions.
Nonetheless, you'll need to show your relationship is genuine, meaning mainly that you have a real intention to live together permanently. Since new regulations came into force in 2010, there is also, in theory, a condition that the marriage not be entered into primarily for immigration purposes. I say "in theory" because after searching, I can't find any example of marriages that have been found to be genuine at the time they occur but also entered into primarily for immigration purposes. The most likely candidates might be some arranged marriages.
That being said, the Canadian Bar Association warned about possible consequences of the amended regulations for legitimate couples not unlike yours.
https://www.cba.org/cba/sections_cship/pdf/immigration_refugee_regulations.pdf
"For example, consider a genuine romance between a Canadian resident and a foreign visitor. They decide to marry, but no date is set. The visitor applies to extend their status, so marriage can be pursued. The visitor extension is denied. The couple must separate, and pursue their application while apart for months and perhaps for more than a year, or accelerate their marriage date so they can pursue their application within Canada. Is the marriage genuine? Yes. Was there a significant intention that the marriage would facilitate acquiring status? Absolutely. However, despite the fact that these circumstances would not ordinarily constitute 'bad faith,' this couple would be vulnerable to refusal of the relationship using the proposed disjunctive test."
It's not clear to me whether the potential for genuine couples to be excluded this way has actually materialized or is still theoretical. Perhaps an expert can point out some cases that shed light on this issue.
