How much data in total do you have? Perhaps 2 or 3 external drives (each large enough to hold all your data) on those laptops could bridge the gap for now. Externals are relatively inexpensive, and using something like Syncthing, they could stay in sync.
I took this approach to consolidate my data to free up drives from machines so I could build a NAS running Proxmox. Then copied that data to the NAS, which is the authoritative data store, the other drives now act as local duplicates.
Alternatively, upgrade the drives in the laptops (depending on how much data you have).
Also, keep in mind growth - once you have your data sorted, watch it grow and use that to predict your need for new storage.