I would also recommend myQNAPcloud storage - it is extremely cost effective compared to other cloud storage solutions.
I also use iDrive to backup my data to the cloud. Don’t use the new iDrive backup feature for QNAP that works with HBS. The cost is WAY too expensive. Instead set up a normal iDrive account and use their backup app available in App Center. I have about 14TB of storage on their system now. And the price is very reasonable.
So everything is backed up to my iDrive account. I backup “critical” items (< 1TB) to my myQNAPCloud storage account since it is about 3 times the cost of the iDrive account but it is easier and integrates better with the QNAP.
I also backup my data between to NAS units and also do snapshots, etc. I have multiple copies of everything now in multiple places. I recently realized that I lost a large amount of personal projects, videos, data, etc from years ago that were on a computer that was not properly backed up and I thought I could just pull data off the drives after ten years of it sitting there. Nope. Nearly every drive failed. So now I am not going to make that same mistake!
As far as bandwidth usage, it took about 2 to 3 weeks to upload everything to my iDrive account at 40Mb/s upload. iDrive has a service where they can send you a hard drive where you can then backup files to that and ship it back to them to load into your account. It was not any faster than just uploading the data quite honestly! But now that everything is uploaded both on myQNAP and iDrive, the bandwidth usage is minimal as backups are all incremental.