iPhone Mirroring unfortunately won't work when you are signed in with an EU Apple Account in the App Store and are physically in the EU. If you travel outside the EU it will work...
I have read that you could switch your App Store account to a non-EU Apple Account. For some regions you would need to set a payment method (but apparently not for Canada, so you could choose that) and a real address (make something up, I guess?).
However, this means:
- losing access to current subscriptions
- losing access to media (Apple Music, Purchased Music, Purchased Books, Movies, TV Shows,...)
So I suppose you could make it work if the tradeoff is worth it.
It's unfortunate that we as EU citizens suffer the consequences of the EU and Apple's 'beef' with each other.