Can you forfeit or surrender?
You cannot forfeit

From the Season 1 FAQ:


  Is it legal to quit a game without finishing it because it's a lost cause, in particular, this would prevent additional panic stickers from being placed in case of outbreaks. Or, are we forced to sit there and see it through to the end?
  
  
    You are supposed to play until you actually lose.
  


So unless the Season 2 rulebook specifically states otherwise, it is reasonable to apply this rule to both seasons. The rulebook justification for this FAQ entry is that the rules for how the game can end do not include forfeiting as one of the ways it can end. The rulebook lists all possible ways for the game to end.