Sonshine28:
So if I (not really me but someone close to me) am traveling on business and I make an effort to go to Mass on All Saints Day but the little church I try to go to has changed the schedule to such that I cannot attend because of my work schedule, then: Am I missing Mass on a Holy Day of Obligation? (But it’s not apparently a Holy Day of Obligation in Canada) or Do the rules of my home diocese apply whether I’m traveling or not?
Umm…you realize All Saints Day was yesterday, right?
In any case, here’s how it works.
All Saints Day is a universal Holy Day of Obligation. So it’s a universal law.
Canada (or we could say ‘the people in Canada’) are released from that universal law by the fact that the Canadian bishops requested and received permission from the Holy See to remove the obligation.
As a traveler, when you visit a place that has been exempted from a universal law,
the exemption applies to you the traveller.
Canon 12 §1. Universal laws bind everywhere all those for whom they were issued.
§2. All who are actually present in a certain territory, however, are exempted from universal laws which are not in force in that territory.
Therefore: No. You would not be missing a Holy Day of Obligation if you are in Canada on All Saints Day. Not you, nor any other person in Canada, whether resident or traveller.