Azure SQL Managed Instance is fully-managed SQL Server Database Engine hosted in Azure cloud. With Managed Instance you can easily add/remove cores associated to the instance and change the reserved size of the instance. You can use PowerShell to easily manage size of the instance and automate this process. As a prerequisite, you need to... Read more

https://blogs.msdn.microsoft.com/sqlserverstorageengine/2018/05/31/change-size-azure-sql-managed-instance-using-powershell/