I have a synology NAS where I backup my photos to. What would be the most cost effective way to encrypt and back up this data without having to purchase another NAS and install it at a family member’s house. It would be about 5 TB and would not touch the data unless my NAS completely takes a crap.
I’ll also vouch for Backblaze’s B2 plan; works well with Synology, and has great reporting options to let you know if you’re approaching your budgeted value, and web-based browsing tools to verify what data they got successfully sent to them.