I have 14 drive bays (configurable up to 18) and plan to populate them with 18tb iron wolf pro drives. However at first I will only have 4-5 drives and will expand later as storage demands

I plan to have an off-site backup and have the hardware for it but have yet to configure it.

How do I configure the drives so I am not loosing huge amounts of drives to redundancy but can also rebuild my array without another drive dying from the stress of rebuilding?

Downtime is not a concern of mine.

All of the data is replaceable albeit with extreme effort. Anything irreplaceable is stored separately on multiple sets of drives in multiple locations (mostly cold storage, some hot storage)