End of a chapter: I landed last weekend!
I was first going to do it at the CIC office in Ottawa, since there are walk-in hours every other Tuesday and they're a few minutes from my office. But apparently they have a bad grip on the rules for outland applications. First they asked for extra photos, while the one on the COPR should be, and in the end was indeed enough. They also wanted my wife to be there and for us to proof that we live at the same address, but for outland applications that should not be necessary. We do obviously, but my wife can't make Tuesdays due to work.
So in the end it was just easier to drive down to the Prescott border crossing, about an hour from here.