Many Canadian organisations need personal or regulated data to stay in Canada. All three major clouds now offer Canadian regions, but residency is about more than choosing a region in a drop-down.
Some managed services replicate metadata, logs or backups to other regions by default. Global services such as DNS, CDN and identity may process data elsewhere. The first job is an inventory of every service in your architecture and where each one stores and processes data.
Next, enforce residency with policy rather than good intentions: service control policies or Azure Policy that deny resource creation outside approved regions, and encryption keys held in Canadian key management services.
Finally, collect evidence continuously. Automated configuration checks and a documented data flow diagram make audits and customer security questionnaires far less painful.