This is a great question, and I agree with Dr. Turnbull that there isn't an easy explanation.
Starting to think creatively about it, this is where a potential conversation might come in about MPs who are designated for overseas voters, for example. I know that was part of the debate during the last committee meeting with the previous two witnesses.
I think it will require outside-the-box thinking, because I don't think it makes much sense to tie people to the riding in which their family used to reside a generation ago. I think there will need to be a different approach.