If this would allow me to check my files in a simple web UI (no need for collaboration or anything), and create share links for low-volume downloads I could just leave Google Drive permanently.
Requires extra data transfers and extra storage, but for small files that seems doable without invalidating the master password setup. You do end with two separate encryption systems, though.
A more scalable solution would be to encrypt every file with a different key and encrypt the key store with the master password (but that would obviously require a relatively extensive rewrite). You'd be able to get more fine-grained file access without sacrificing the single master password setup.
That way, you can simply share the file key when you want to generate a share link.
Here's an example secret link: https://peergos.net/#%7B%22secretLink%22:true%2c%22link%22:%...
It's P2P, fully open source including the server, self-hostable, audited by Cure53, can use S3 compatible block storage or local disk and built on top of IPFS.
I'm a little paranoid about avoiding SAAS out of China.