Option #1 looks best to me, I'd say look into a cloud connector solution.
Cloud connectors integrate a cloud storage measure into your traditional surveillance system. For specialist cameras, you just need to add one alongside your existing NVR and upload footage straight to the cloud.
There's some good info on this technology in this article: https://www.chrislewis.co.uk/blog/cloud-cctv-what-can-it-do-for-me