Could I jump in with a reply?
Thank you for the question. It's a great one, and this topic is a very important one.
I will preface my remarks by pointing that that in Canada, forever, taxation has occurred when a taxable event occurs. You or I will pay GST or HST when we purchase a good or a service. If we don't purchase a good or a service, we don't pay GST or HST, and so on and so forth. All taxes are tied to a taxable event.
The challenge in making Canada more like the U.S., if that would be the right way to go, is to define what the taxable event is when a Canadian expatriates himself or herself because of their job, because of their family, because of engagement overseas. I think we can assume that this was a good thing without going into too much detail. Define the taxable event that has occurred. It's different, as you have just mentioned, from a Canadian who stays in their home riding or constituency.