I know OCI isn't popular around here, but it ticks all the boxes you listed. Managed Postgres, Terraform, and Toronto/Vancouver regions. It'll end up being roughly half the cost of AWS at list for your average EC2/RDS/S3 workload.
That said, part of the desire to get off AWS is finding slightly less nefarious set of characters to hand money to and Ellison (and his lot) doesn’t fit the bill.