Bulk Upload Files stored in QB to SharePoint with Pipeline

I don't see why not. I haven't used the Sharepoint channel specifically as opposed to Box or Drive - but conceptually you would just loop through your records with a single Pipelinesand move them all via a simple process. 

Since you're moving so many - your best bet is to do it in Batches of a couple of hundred at a time in case Pipelines times out since it will probably take a while. As part of the Pipeline you would: 

1. Query for Documents that haven't been loaded yet
2. Upload to Sharepoint
3. Tag the record in Quickbase with the Sharepoint ID so you can build a url/link to get it from Quickbase
4. Delete the file in the record/attachment field (optional)
5. Move on to the next record in your loop

Your setup would be to look for records that don't have that sharepoint ID. You also don't have to delete the file right away. You could leave the file in QB for now until you feel confident that the transfer went well and then do the process to either delete the file attachment field altogether or delete the files for good measure.