First time?

Last year I also worry like you. Like people gone, short-staff, how to finish?

But I remember my senior manager just smile at me, say he see this for 10 years already.

End of the day, the firm is huge machine that isn't going to stop because of 1 person.

Realistically, if its a non-listed co, and the timeline can be managed, they will push back the date.

If cannot be pushed back, depends either the existing staff will just tank more work, or the manager will "borrow" people from other less urgent cases to come fire fight.

At that point in time it will sound like fire, but 1 year later you look back, everything solved. Nobody died, life goes on.