I would like to elaborate a bit more on option 3. SSIS packages. I tested the solution and it sorta worked. First of all - SSIS IR is super expensive and You would like to use http post's to start-stop it while it is not needed.
Secondly, SSIS does not support processing blob files out of the box. There are some ways around it. You can use some third-party soft (didn't try that), or explore options
In my case I used trick to deploy package that download file locally, process and then delete it. Since SSIS IR is a VM, it basically did the same on IR after deployment. It was a trick rather than solution and it was not 100% stable. Another issue - numeric fields got some insignificant error during processing - eg. uploading 25 resulted in 25.0000000001 at db site. No idea why. I did not have enough time to investigate issues deeper.