The 60 (calendar) day timeframe provided by the FDA is not a commitment or promise. They can and routinely take longer to provide feedback/responses. With the holidays, a delay of a week or 2 could definitely be expected (but they could still be on time). I work for a company like Samsung Biologics and have clients receive feedback from the FDA outside of their 30, 60, 90 day windows frequently. Like them or not, the FDA is slammed with the pandemic.
This is just to set realistic expectations should January 5 roll around with no news.