Google has updated their status on the fix with the following; the time zone is in ET:
We expect to resolve the problem affecting a significant subset of users of Gmail at 12/15/20, 7:00 PM. Please note that this time frame is an estimate and may change. The affected users are able to access Gmail, but are seeing error messages, high latency, and/or other unexpected behavior.
Updates for GMails downtime can be found here: https://www.google.com/appsstatus#hl=en&v=issue&sid=1&iid=a8b67908fadee664c68c240ff9f529ab