The longest filibuster on record is only 24 hours! Do it, Harry! DO IT!
That 24 hour filibuster was only one Senator. All of the Senators in theory would get a chance to speak. So if the Democrats were to filibuster and each Senator took a whole day, thats 44 days of debate. During that 44 days you couldn't transact other important business in the Senate because the floor would be held up by the issue being filibustered.