There's a zillion things you can do and implement for those kind of situation. If I was you, I would at least start by having:
- At least a spare laptop/computer in each branch, ready to go
- An image ready to be deployed on a laptop I need to reinstall with minimal configuration afterwards (only employee specific stuff)
- A remote monitoring/remote control app like Meshcentral, to be able to fix (most) issues without driving to the branches
I don't know if your company use GSuite for all their needs (docs, emails, etc). If the answer is yes, then it might be difficult to migrate from GDrive, but otherwise, I would replace it with something else.
If your salesperson need to look for a customer name INSIDE their files, they are not storing/naming them efficiently. I don't know the business you are in, how many customers you deal with and how many invoices a customers can have but here's a few ideas:
Invoices/Customer XYZ/2023-10-16 Invoice 1234.pdf
Invoices/Customer XYZ/2023-10-16 Computer Replacement Project.pdf
Invoices/2023/2023-10-16 Customer XYZ - Invoice 1234.pdf
Projects/Customer XYZ/Project Name/Date - Invoice Number - Whatever.pdf
That's just examples, but I would say that the kind of "metadata" they are looking for should be somewhere else than just in the content of the files