Honestly, I think with your profile you're a longshot for anything in the top ~15 as it stands right now. I'm less familiar with other programs so maybe someone else has input. Work on getting ODE and calculus based probability /mathematical statistics (this is crucial, I would argue it's more important than ODE).
You mentioned taking an extra year in undergrad, I can't directly recommend this but it's a personal decision for you. You're in Canada so I'm not positive how the costs work out (Compared to the US where we're paying an arm and a leg for university but thats a different topic) but I don't recommend putting yourself in crippling debt just to make yourself more competitive for these programs.
Let's say you do take an extra year and you try and lock down some of these critical prereqs. I think you'd need to boost your GPA (hopefully around 3.8 but an upward GPA trend is also good) and your GRE Quant (just a little higher, I think 167 is a good target). If you get some good letters of rec, strong personal statements and interviews along with all the above, you probably have a good chance at Fordham, GA Tech, BU, and Tandon and an outside shot at some of the higher ranked programs.
I'd also like to reiterate what Andy said about learning how to program. I think thats a good focus to at least break in to the field. These Master's programs are not the be all end all of quantitative finance. If, however, you do decide to pursue a Master's, then there are certainly some steps to take to become a more competitive applicant.
I suggest you look into each program on the quantnet rankings into what they're looking for from applicants (Berkeley MFE has a nice itemized page of all their prerequisites as do most schools, for example UoT can be found here:
mmf ★).
One last note, you say you don't have any finance work experience, what about any internship experience? You're presumably a junior, do you have any plans for this summer? A relevant internship (especially one where you do a lot of coding) is definitely a major plus.
