Sure enough, after making the minimum donation of $5 (plus an extra dollar donation taken as a "tip" by GSG), well, it seems to have worked:
So this proves that 1) yes, you can donate, and 2) absolutely no one is interested.
P.S. The charge on my Visa card was exactly six dollars, so there's appears to be nothing to the speculation that that initial 13 dollars was 10 dollars U.S. It's clear my donation was processed normally in Canadian funds. Make of that what you will.