The SFTP-SSH Connector supports files up to 1GB with chunking enabled. Chunking needs to be set in the action settings.
But note that all actions don't support working with this chunked data. To work around this, you could employ Azure Functions to process the data with Logic Apps implementing the business workflow you require.
The Logic App would have to be something like this
- Trigger based on your business requirement
- Fetch file from SFTP
- Create file in blob storage with the fetched content from above
- Call Azure Function with path to created blob to process it and place the final XML file back in blob storage, returning the path to the new blob
- Fetch file from blob storage using path returned from function
- Create file in SFTP using the fetched content from above
As for the Azure Function, you could leverage the blob storage bindings to interact with blob storage with your function focused on processing the file.