The only Amtrak crewing of trains I know of on CN besides the Cascades, where a precedent was set must be 100 years ago by the Great Northern, is 2 miles to Niagara Falls, ON and that bridge belongs to either Amtrak or NYSDOT.
Union turf battles are established by precedent and they have long memories.
Well, Amtrak/NYDOT ownership of the Whirlpool Bridge takes over close to the very close to the east end of Niagara Falls, ON platform. The CN Grimsby Sub's MP 0 is apparently the the bridge (since it is notated as BRIDGE, Amtrak control extends to MP 0.47. CN CTC ends at MP 0.6, which is just east of the station, IIRC.) It isn't a mile or two, if BRIDGE is the middle of the bridge then Amtrak control extends it almost 1/2 mile from its center, which is close to the station. Amtrak operates for a matter of mere yards over CN rail there, at most. My guess is 0.13 miles between the end of CN CTC and Amtrak represents CN owned track fronting platform the Niagara Falls platform, so GO Transit/Metrolynx trains don't have to officially have anything to do with Amtrak, just CN.
I remind you of the subject of this thread, the Adirondack, operates over CN with Amtrak crews in Canada (and another few yards in the US) from just north of the Rouses Point station to where ever EXO takes over ownership in Montreal. That is addition to the Cascades.
I was responding to your contention that the fact that VIA's operating crews were without conductors could somehow be an issue here, not Union jurisdiction and turf. My point was VIA's crew practices has nothing whatsoever to do with Amtrak's ability to operate over CN in Canada. I actually agree with your and jis' point that one of the stumbling blocks to Montrealer resumption is likely tied up in some kind of Union jurisdiction hairball. Even extending to what union controlled which turf back before Amtrak or VIA, irrespective current ownership or operational control. Regardless of how long it goes back, it still is part of the Union jurisdiction/turf fight hairball, it has absolutely nothing to do with VIA and their conductor-less operations.
As to Amtrak employing employees based in Canada, well, they'd have to deal with compliance and registration with foreign country's employment, HR and other rules, which is monstrous headache for any organization, let alone a railroad, let alone a government-sponsored one, especially when we are talking on the order of like just 10 employees. Plus whatever issues the union's may have over jurisdiction probably applies to Amtrak staff whether the are based in Vermont or Quebec. If union issues could be solved, an hours of service issue, if any, could be solved by putting a short crew district from, say, White RIver Junction to Montreal. It could be handled like the short district from Reno to Winnemucca. On the CZ, crew works from Sacramento to Reno, rests, works from Reno to Winnemucca and back, rests, works Reno to Sacramento. Something like could be possible or just flat out another crew base established. Either would be a lot easier than than basing Amtrak employed crews in Quebec. In any case, the real rub is union jurisdiction issues, not VIA lacking conductors, hours of service, or where the crew are employed. If jurisdiction could be settled, the rest could probably fall into place relatively easily.
Of course, since it is my understanding that neither Vermont nor Quebec are remotely interested in sponsoring a resumption of the Montrealer, the whole thing is probably moot, anyway.
