Hopefully founders had thought of this before starting and kept a tab on burn rate. Its surprisingly how little humans need to survive in adversity. Tons of businesses in India run on a razer thin cashflow margins (e.g. clothing industry) where the credit runs for 60-90 days and even if one client delays it brings the business to a halt. Having said that, you never want to put yourself and your employees thru this nightmare and you should give them enough time or at least share with them complete information so that they can decide if they want to stay back or not.
I have been a part of a company in US where the entire workforce of over 30 people had to go on half their paycheck for 2 months during Chritmas because of cashflow issues. Again, if you treat everyone well people do stick it thru your thick and thin.