It's pushing the boundaries of a spreadsheet's practical usability to be honest. I would not use it for more than a few hundred at most. In fact I just checked my largest sheet is 292 rows. Anything larger goes in anything else! Usually I use SQLite for local storage data like that now.

A funny problem I had a few years back was a company with users keeping 200 meg+ Excels sheet on their desktops. It took them forever to log off every day because the profile was copied back to the server.