Ask HN: Google Drive/Office 365 alternatives

My partner runs a small charity in the UK whose office infrastructure is based on Google Drive. (Sheets, spreadsheets, email, etc). Her trustees are advising that since Google cannot guarantee that her data is being stored in the UK (apparently?), they need to migrate. Like seemingly every organisation these days, they're looking at MS Office 365. But having a partner with GNU and emacs stickers all over their laptop, she's wondering what alternatives are out there. It'd need to be low (or better no) maintenance, comparable in cost to Office 365 and quality too. It could be web-hosted or based on Next/OwnCloud or something, as long as it works without a load of pain points. Oh and UK-hosted too. I assume others here must have thought this through already, so thought I'd ask the hivemind!