Travel anywhere near the USA.
It's not just a question of where the conference is held. If you travel via a US airport you're deemed non-airside and basically imported with your luggage and the aforementioned checks (suspicion/indignities) before being promptly exported with the same again. Of course, the fact that you set out with no intention to set foot in the good ole' US of A seems to be taken as some kind of international slight.
Once in the US of A I've always found the people I meet to be kind, interesting and interested. It's getting through that barrier that for me is no longer worth it.
I appreciate the OP pointing out that Canadas Border agency are only just behind, but I have a feeling they apply it with more good humour and dose of common sense. Can't wait to visit. PP
Icon.>>> Keep your Montana mountain base. I'd feel safer with "our friends in Hereford".