Using a difference source for a document library

We're aware that SharePoint storage is limited, based on the number of M365 E-type licenses we have.  We have groups of people that have been uploading terabytes of data into SharePoint, since it's easy and fairly quick.  However, we are running low on disk space and it's $0.20 per additional GB per month.  We have other cloud storage options that are much cheaper. 

Is there a way to retain the Teams/SharePoint interface but point a document library to a different storage option, and not use the default document library?  Maybe like have a drive mapping or UNC path appear within SharePoint or Teams?  I'd like to be able to not use the document library that comes with SharePoint, but open up another storage location from within SharePoint, if that makes sense.