Actually, our ATUM Multi-Inventory Add-on it was created to achieve what you want. Go to the ATUM left menu - Settings - MultiInventory - and Select 'Shipping zones' as Region Restriction Mode. Then go down and activate Geo Prompt (this allows the geolocation) - Save Changes.
Once this is enabled, you have to set regions to each inventory of the multi-inventory products.
I leave you here the documentation where you can find more info: https://forum.stockmanagementlabs.com/t/region-restriction-mode
Hope this helps, and if you have any doubt don't hesitate to ask.