I would recommend Le Bon Usage. The online version is probably a boon since it can be somewhat challenging to search in the paper version. It is very extensive, is replete with examples, and includes advanced constructs too.

This project has been a long time coming. I sort of remember people working on it during the early 2000, but the first paper published about it I found dates from 2007.

Anne Abeillé‘s webpage has an entry for La Grande Grammaire dated 2021. As she has been the co-director of the project since the beginning, it might appear next year.

A. Abeillé, D. Godard (dirs) 2021. La grande grammaire du français,
Actes Sud