hope I'm not suggesting things you already know / tried. likely best to start with the forum vendor spreadsheet,
to determine who has instant, then contact through vendor website (or here, but may take longer) and see if they ship to Canada.
we've had (and truly love) instants from
@Gourmet Hawaiian Kava and instant green
@Bula Kava House . n@h also has fire island instant and
@Henry (of The Kava Society-New Zealand) has an instant, neither of the above have we tried, yet but hear lots of good things from folks here.